Optoelectronics Test
OPTOELECTRONICS TEST
Optoelectronics Test
키슬리 공식 채널파트너
Optoelectronics Test
Technical Information . . . . . . . . . . . . . . . . . . . . . 318
Pulsed Laser Diode Test System . . . . . . . . . . . . 321
2520INT
Integrating Sphere for Pulsed Measurements . . 326
System 25
Laser Diode LIVTest System . . . . . . . . . . . . . . . . 329
Series 2400
SourceMeter ® Instruments . . . . . . . . . . . . . . . . . 332
2502
Dual-Channel Picoammeter
for Photodiode Measurements. . . . . . . . . . . . . . . 335
2500INT
Integrating Sphere . . . . . . . . . . . . . . . . . . . . . . . . . 336
2510
TEC SourceMeter Instrument . . . . . . . . . . . . . . . 339
2510-AT
Autotuning TEC SourceMeter Instrument . . . . 339
8542, 8544,
8544-TEC
Laser Diode Mounts for LIV Test Systems . . . 343
7090
Optical Switch Cards . . . . . . . . . . . . . . . . . . . . . . 344
OPTOELECTRONICS TEST
2520
Side Text
Selector Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
070-7872-0703
키슬리 공식 채널파트너
317
Active optoelectronic device
characterization requires more
than a current source
a very small, precise reverse current (10nA)
while measuring the voltage. The limited current prevents permanent damage to the device,
while allowing a precise breakdown voltage to
be measured. Given the breakdown voltage, it’s
now possible to force a reverse bias that won’t
harm the device while leakage is measured. This
leakage current value is often used to qualify the
device for further testing.
Technical information: Optoelectronics
Side Text
test
Forward
Voltage
(VF) V
L
IBD
Back Facet
Detector
Current
(IBD) A
dL/dIF
VF
Light Power
Output
(L) mW
Four-quadrant source capabilities
+1A
Kink Test
(dL/dIF)
IF
Forward Current (IF) mA
+100mA
Figure 1. Classic LIV curves associated with
semiconductor laser diodes.
Active optoelectronic devices are basic semiconductor junctions. To be fully tested, they require
not only forward I-V characterization, but also
reverse I-V characterization. While conventional
laser diode drivers are valuable for providing
drive current in the optics lab, these current
sources aren’t suitable for developing a complete understanding of a semiconductor device.
The SourceMeter® line provides a full range of
source and measure capability optimized for
semiconductor characterization.
I
VF test
V
I L test
–200V
–20V
+20V
2400
only
+200V
2400
only
–100mA
Duty cycle
limited
–1A
Figure 3. The Model 2400 can source or sink
either current or voltage. Other SourceMeter
instruments offer different ranges, providing
a very wide dynamic range from as low as a
1µA range or 200mV to 5A or 1000V.
The SourceMeter product line combines a full
four-quadrant precision source (see Figure 3)
with measurement capability. Source and measure ranges provide a very wide dynamic range
from as low as a 1µA range or 200mV to 5A or
1000V. These very wide dynamic ranges allow
testing diverse devices from delicate AlGaAs
laser diodes to silicon avalanche photodiodes.
Imeter
VR test
Isource
Local
IN/OUT HI
Remote
SENSE HI
Vmeter/Compliance
OPTOELECTRONICS TEST
DUT
Figure 2. Characterization of semiconductor
junctions requires measuring reverse breakdown (VR), leakage current (I L ), and forward
­voltage (VF).
A complete characterization of an active optoelectronic device requires forcing both forward
and reverse currents and voltages. For instance,
the reverse breakdown test requires sourcing
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Remote
SENSE LO
Local
IN/OUT LO
Imeter/Compliance
G R E A T E R
IN/OUT HI
Remote
SENSE HI
Vmeter
Vsource
DUT
Feedback to
Adjust Vsource
Remote
SENSE LO
Local
IN/OUT LO
Figure 5. In voltage source mode, a
SourceMeter instrument forces a voltage and
measures current. Remote sense of the voltage ensures the desired voltage at the DUT.
Verifying device connections
Series 2400 SourceMeter instruments all offer
the Contact Check option, which automatically
verifies all test leads are connected to the DUT
prior to energizing the test leads or executing
a test sequence. Figure 6 shows Contact Check
identifying a disconnected remote sense test
lead. Without the sense test lead connected, the
voltage compliance couldn’t be controlled during test execution.
GUARD
Imeter
Pass
350µs
Contact Check
GUARD SENSE
IN/OUT HI
SENSE HI
V or I
Source
Vmeter
Fail
(optional)
SENSE LO
Pass
IN/OUT LO
Figure 6. The contact check option verifies the
force, sense, and guard test leads are properly
connected to the DUT before testing begins.
Remote voltage measurement
SourceMeter instruments offer two- or four-wire
measurement configurations. Two-wire voltage
measurement shares test leads with the source
as shown in Figure 7a. When sourcing high
currents, the voltage drop across the test lead
becomes significant with respect to the forward
voltage across the DUT.
Figure 4. In current source mode, a
­Source­Meter instrument can force current
while measuring voltage. The remote voltage
sense ensures the programmable voltage
compliance isn’t exceeded.
A
Local
-
Optoelectronics Test
+
Technical
Information
M E A S U R E
O F
C O N F I D E N C E
Technical
Information
+
SourceMeter
Output
LO
-
Sense
LO
Figure 7a. Two-wire measurement
Output
HI
Sense
HI
+
SourceMeter
Output
LO
-
Sense
LO
Deterministic trigger I/O
Conventional instruments typically support a
simple trigger in/trigger out convention. The
challenge to the engineer is controlling the
trigger interaction between instruments. It is
often that case that simple trigger I/O doesn’t
allow for differences in instrument behaviors or
synchronization of multiple instruments. Figure
9 shows the trigger scheme available on most
optoelectronic instrumentation.
Input
Trigger
Meter Operation
(A/D, Close Channel, etc.)
Output
Trigger
Figure 7b. Four-wire or Kelvin measurement
Figure 9. Typical trigger input/output scheme
Four-wire voltage measurement uses dedicated
test leads for measuring the voltage drop across
the DUT. Since the voltage measurement circuit
has very high impedance inputs, the current
through the measuring test leads is low. The IR
drop across the measurement test leads is an
extremely small fraction of the voltage dropped
across the DUT.
A Series 2400 instrument breaks the measurement cycle into three parts, as shown in Figure
10. The three components are the source phase,
delay phase, and measurement phase (also
known as the SDM cycle.) The Series 2400 trigger model allows each phase in the SDM cycle
to be programmed so that it can be gated by an
input trigger and also to be programmed so that
completion of each phase generates an output
trigger.
SourceMeter
Output HI
Metal Case
Standoffs
RL1
A
x1
Guard
RL2
Metal Plate
While many instruments are limited to a single
trigger in and single trigger out, Series 2400
instruments use a Trigger Link.
Before
Source
Before
Delay
Before
Measure
Series 2400
Input Triggers
Output LO
Figure 8. The cable guard circuit drives the
guard conductor at the same potential as the
output HI conductor.
Low level current measurements require a driven guard
Unique to precision measurement equipment,
the driven guard minimizes the electrical potential difference between the conductors that surround the source test lead and the test lead (see
Figure 8). When the electrical potential between
the source test lead and guard test lead is low,
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S
D
M
Source
Delay
Measure
(Sense)
After
Source
After
Delay
After
Measure
Series 2400
Output Triggers
Figure 10. Series 2400 instrument’s trigger
input/output scheme
Precision characterization of active optoelectronic components often requires multiple instruments working together. For instance, two Series
2400 instruments can be used together: one
Source­Meter instrument to drive the device and
A
G R E A T E R
another SourceMeter instrument connected to a
photodiode to record the optical output of the
active device. Figure 11 shows two Series 2400
instruments working synchronously together to
characterize an LED.
2400 #1(LED)
INIT
TRIG:INP SENS
Line #1
S D M
TRIG:OUTP SOUR
Line #2
2400 #2(PD)
TRIG:INP SOUR
Line #2
S D M
TRIG:OUTP DEL
Line #1
Figure 11. SDM triggers to synchronize two
Series 2400 instruments.
Notice how trigger in and trigger out are tied
to different parts of the SDM cycle to ensure
that measurements on the LED and the PD are
made at the same time. This same technique can
be applied to ensure that the source current is
stable prior to making an optical spectrum measurement with an additional instrument.
Complete DUT protection
DUT protection is a major concern for optoelectronic devices. SourceMeter instruments are
ideal for providing a safe electrical environment
for delicate active optoelectronic devices.
Technical information: Optoelectronics
Side Text
test
Sense
HI
the potential leakage paths are neutralized. This
technique requires an additional instrumentation amplifier that senses the output of the
programmed source and drives the guard circuit
with the same potential with enough current to
overcome any leakage between the guard components and ground.
• Normal output off mode drives the output
terminals toward 0V. This action de-energizes
the device and more importantly the inductive test leads. The rate of discharge can be
controlled with the source range settings.
This provides a better environment than
shorting relays in conventional laser diode
drivers.
• SourceMeter instruments provide programmable compliance, range compliance, and
voltage protection settings to ensure that
the DUT isn’t subjected to excess voltages or
currents.
• Contact check ensures all test leads are in
contact with the DUT prior to energizing the
device.
In addition, the SourceMeter family is built on
a heritage of precision semiconductor test and
characterization of much more sensitive devices
than active optoelectronic components.
M E A S U R E
O F
OPTOELECTRONICS TEST
Output
HI
Optoelectronics Test
C O N F I D E N C E
319
Selector Guide
Optoelectronics Test
LIV Test Systems
2602A
Page
Selector guide: Optoelectronics
Side Text
test solutions
Max. Drive Current
Source Mode
2612A
10
10
3 A DC /
1.5 A DC /
10 A pulsed per channel 10 A pulsed per channel
DC
Pulse / DC
(Continuous Wave)
(Continuous Wave)
1 Laser Drive,
1 Photodiode
Number of Channels
System 25
2520
329
321
5A
5A
DC
(Continuous Wave)
Pulse / DC
(Continuous Wave)
1 Laser Drive,
2 Photodiode
1 Laser Drive,
2 Photodiode
1 Laser Drive,
1 Photodiode
Photodiode
Measurement
Optical Power Measurement
2502
6487
6485
2635A/2636A
335
110
107
10
15 fA
20 mA
100V
(each channel)
20 fA
20 mA
20 fA
20 mA
120 fA
10 A
500 V
none
200 V
2500INT Series
(Si & Ge)
(190nm – 1800nm)
2
3-slot Triax
2500INT Series
(Si & Ge)
(190nm – 1800nm)
1
3-slot Triax
2500INT Series
(Si & Ge)
(190nm – 1800nm)
1
BNC
GPIB, RS-232
GPIB, RS-232
GPIB, RS-232
Page
CURRENT MEASURE
From
To
PHOTODIODE
VOLTAGE BIAS
FEATURES
Optical Measurement Head
Number of Channels
Instrument Connection
Communication
1/2
3-slot Triax
GPIB, RS-232,
Ethernet (LXI)
Laser Diode and LED Current Drivers
Page
2601A
2611A
2401
2420
2440
2520
6220
6221
10
10
332, 33
332, 33
332, 33
321
97
±10 pA
±500 pA
±500 pA
70 µA
80 fA
±1.05 A
±3 A
±5A
+ 5A
±100 mA
DC
DC
DC
DC/Pulse
DC/Pulse
CURRENT SOURCE
From
To
OPTOELECTRONICS TEST
Type
5 pA
5 pA
3 A DC / 10 A pulsed 1.5 A DC / 10 A pulsed
per channel
per channel
DC/Pulse
DC/Pulse
VOLTAGE MEASURE
From
To
1 µV
40 V
1 µV
200 V
1 µV
21 V
10 µV
60 V
10 µV
40 V
60 µV
10 V
10 nV (w/2182A)
100 V (w/2182A)
Screw Terminal
Screw Terminal
Banana
Banana
Banana
10W BNC
GPIB/RS-232, TSP,
Ethernet (LXI)
GPIB/RS-232, TSP,
Ethernet (LXI)
GPIB/RS-232
GPIB/RS-232
GPIB/RS-232
GPIB/RS-232
3-slot Triax
GPIB/RS-232,
Ethernet
(6221 only)
FEATURES
Instrument Connection
Communication
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A
G R E A T E R
M E A S U R E
O F
C O N F I D E N C E
The Model 2520 Pulsed Laser Diode Test System
is an integrated, synchronized system for testing
laser diodes early in the manufacturing process,
when proper temperature control cannot be
easily achieved. The Model 2520 provides all
sourcing and measurement capabilities needed
for pulsed and continuous LIV (light-currentvoltage) testing of laser diodes in one compact,
half-rack instrument. The tight synchronization
of source and measure capabilities ensures high
measurement accuracy, even when testing with
pulse widths as short as 500ns.
LIV Test Capability
The Model 2520 can perform pulsed LIV testing
up to 5A and continuous LIV testing up to 1A.
Its pulsed testing capability makes it suitable for
testing a broad range of laser diodes, including
the pump laser designs for Raman amplifiers.
The instrument’s ability to perform both DC and
pulsed LIV sweeps on the same device simplifies
analyzing the impact of thermal transients on
the LIV characteristics of the laser diode.
• Simplifies laser diode LIV testing
prior to packaging or active
temperature control
• Integrated solution for in-process LIV
production testing of laser diodes at
the chip or bar level
• Sweep can be programmed to stop
on optical power limit
• Combines high accuracy source and
measure capabilities for pulsed and
DC testing
• Synchronized DSP based
measurement channels ensure highly
accurate light intensity and voltage
measurements
• Programmable pulse on time from
500ns to 5ms up to 4% duty cycle
• Pulse capability up to 5A, DC
capability up to 1A
• 14-bit measurement accuracy on
three measurement channels (V F,
front photodiode, back photodiode)
• Measurement algorithm increases
the pulse measure­ment’s signal-tonoise ratio
• Up to 1000-point sweep stored in
buffer memory eliminates GPIB
traffic during test, increasing
throughput
• Digital I/O binning and handling
operations
Maximize Throughput and
Eliminate Production Bottlenecks
By working in cooperation with leading laser
diode manufacturers, Keithley designed the
Model 2520 specifically to enhance chip- and
bar-level test stand yield and throughput. Its integrated design, ease of use, high speed, and high
accuracy provides a complete solution to help
laser diode manufacturers meet their production
schedules. Producers of laser diodes face constant pressure to increase test throughput and
Remote Electrical Test Head included
optimize return on investment for their capital
equipment used in production testing. Until
recently, these producers were forced to use relatively slow and cumbersome test stands for testing
laser diodes at the chip and bar level, which often led to production ­bottlenecks.
Higher Resolution for Higher Yields
To achieve the required signal-to-noise ratio,
traditional chip- and bar-level LIV testing solutions have required the use of boxcar averagers
or test system control software modifications to
allow averaging several pulsed measurements.
The resolution of these measurements is critical for the “kink” test and threshold current
calculations. With earlier test system designs,
particularly when performing the kink test,
low resolution and poor linearity of the analog
digitizer made it extremely difficult to discriminate between noise in the measurement and an
actual device kink. The Model 2520’s unique
DSP-based meas­urement approach automatically
Applications
Production testing of:
• Telecommunication laser diodes
• Optical storage read/write head
laser diodes
• Vertical Cavity Surface-Emitting
Lasers (VCSELs)
• Thermal impedance
• Junction temperature response
• IEEE-488 and RS-232 interfaces
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Multi-channel pulsed
Side Text
test of laser diodes
Pulsed Laser Diode Test System
A
G R E A T E R
M E A S U R E
O F
OPTOELECTRONICS TEST
2520
C O N F I D E N C E
321
2520
Pulsed Laser Diode Test System
Ordering Information
2520
Pulsed Laser Diode
Test System with
Remote Test Head
Multi-channel pulsed
Side Text
test of laser diodes
2520/KIT1
Pulsed Laser Diode
Measurement Kit
(includes 2520, 2520INT,
and 3 ft. triax cable)
Accessories Supplied
User’s Manual, Quick Reference
Guide, Triax Cables (2),
BNC 10W Coaxial Cables (4)
Accessories Available
2520INT-1-GE Integrating Sphere (1 inch) with Germanium
Detector
7007-1
Double Shielded GPIB Cable, 1m (3.3 ft.)
7007-2
Double Shielded GPIB Cable, 2m (6.6 ft.)
KPCI-488LPA IEEE-488 Interface/Controller for the PCI Bus
KUSB-488B
IEEE-488 USB-to-GPIB Adapter for USB Port
Services Available
2520-3Y-EW
1-year factory warranty extended to 3 years from
date of shipment
C/2520-3Y-DATA3 (Z540-1 compliant) calibrations within 3 years
of purchase*
*Not available in all countries
identifies the ­settled region of the pulsed waveforms measured. This means the Model 2520 stores
only that p­ ortion of the pulse that is “flat” and contains meaning­ful data. All measurements made in
the flat portion of the pulse are averaged to improve the Signal-to-Noise ratio still further. If greater
­resolution is required, the Model 2520 can be programmed to perform several pulse and measure
cycles at the same pulse amplitude. By making it possible to conduct more thorough testing at the
bar or chip level, the Model 2520 also eliminates the wasted time and costs associated with assembling then scrapping modules with non-compliant diodes.
Simple, One-Box Test Solution
The Model 2520 offers three channels of source and measurement circuitry. All three channels are
controlled by a single digital signal processor (DSP), which ensures tight synchronization of the
sourcing and measuring functions. The laser diode drive channel provides a current source coupled
with voltage measurement capability. Each of the two photodetector channels supplies an adjustable
voltage bias and voltage compliance, in addition to current measurement capability. These three
channels provide all the source and measure capabilities needed for full LIV characterization of laser
diodes prior to integration into temperature controlled modules. By eliminating the need for GPIB
commands to perform test sweeps with multiple separate instruments, the Model 2520’s integrated
sourcing and measurement allows a significant improvement in throughput.
Remote Test Head Maximizes Signal-to-Noise Ratio
The mainframe and remote test head architecture of the Model 2520 is designed to enhance pulsed
measurement accuracy, even at the sub-microsecond level. The remote test head ensures the measurement circuitry is located near the DUT, mounted on the fixture, minimizing cable effects. As the
schematic in Figure 1 shows, traditional semi-custom systems typically employed in the past require
significant integration. The architecture of the Model 2520 (Figure 2) offers a far more compact and
ready-to-use ­solution.
High Speed Pulse and Measure to Minimize Thermal Effects
The Model 2520 can accurately source and measure pulses as short as 500 nanoseconds to minimize
unwanted thermal effects during LIV testing. Users can program the pulse width from 500ns to 5ms
and pulse off time from 20µs to 500ms. There is a software duty cycle limit of 4% for ­currents higher
than 1A. To ensure greater accuracy, the instrument provides pulse width programming resolution
levels of 10µs (off time) and 100ns (on time).
Prior to the introduction of the Model 2520, test instrument limitations often placed barriers on test
per­formance. However, with the Model 2520, the limiting factor is not the test instrument, but the
Model 2520
High-Speed
Current to
Voltage
Converter
OPTOELECTRONICS TEST
Sequencing
and Signal
Analysis
Computer
GPIB
High-Speed
Multi-Channel
Oscilloscope
Pulse
Source
High-Speed
Current to
Voltage
Converter
322
High-Speed
Current to
Voltage
Converter
Front
Facet
Detector
Voltage Measure
Sequencing
and Signal
Analysis
DSP
Laser Diode
Chip or Bar
Rear
Facet
Detector
High-Speed
Multi-Channel
Digitizer
Parallel Custom Bus
Figure 1. This schematic reflects the current testing practices of
major laser diode manufacturers. Note that the use of discrete test
components increases the integration and programming effort, while
severely limiting the flexibility of the test system.
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Remote Test Head
Pulse I
Source
High-Speed
Current to
Voltage
Converter
2520INT
Laser Diode
Chip or Bar
Rear
Facet
Detector
Figure 2. The Model 2520 integrates synchronization, source, and
measure capabilities in a single half-rack instrument (with remote
test head) to provide maximum flexibility and test throughput.
A
G R E A T E R
M E A S U R E
O F
C O N F I D E N C E
2520
Pulsed Laser Diode Test System
ESD Protection
A laser diode’s material make-up, design, and small size make it extremely
sensitive to temperature increases and electrostatic discharges (ESDs). To
prevent damage, prior to the start of the test and after test completion, the
Model 2520 shorts the DUT to prevent transients from destroying the device.
The instrument’s 500 nano­second pulse and measure test cycle minimizes
device heating during test, especially when a short duty cycle is used.
Test Sequencing and Optimization
Up to five user-definable test setups can be stored in the Model 2520 for easy
recall. The Model 2520’s built-in Buffer Memory and Trigger Link interface
can reduce or even eliminate time-­consuming GPIB traffic during a test
sequence. The Buffer Memory can store up to 1000 points of meas­urement
data during the test sweep. The Trigger Link combines six independent software selectable trigger lines on a single connector for simple, direct control
over all instruments in a system. This interface allows the Model 2520 to
operate autonomously following an input trigger. The Model 2520 can be
programmed to output a trigger to a compatible OSA or wavelength meter
several nano­seconds prior to outputting a programmed drive current value
to initiate spectral measurements.
Figure 3. This plot illustrates the Model 2520’s pulsed LIV sweep capability. The sweep was programmed from 0 to 100mA in 1mA steps. Pulse
width was programmed at 1µs at 1% duty cycle, providing for a complete
sweep in just 10ms (excluding data transfer time).
Accessories and Options
The Model 2520 comes with all the interconnecting cables required for the
main instrument and the remote test head. Production test practices vary
widely (automated vs. semi-automated vs. manual), so the cable assemblies
from the remote test head to the DUT can vary significantly. To accommodate these differing requirements, Keithley has developed the Model 2520
RTH to DUT Cable Config­ura­tion Guide to help customers determine the
proper cable assemblies to use to connect the remote test head (RTH) to
the DUT.
Figure 4. Model 2520 Remote Test Head
Interface Options
The Model 2520 provides standard IEEE-488 and RS-232 interfaces to
speed and simplify system integration and control. A built-in digital I/O
interface can be used to simplify external handler control and binning
operations.
OPTOELECTRONICS TEST
Additional LIV Test Solutions
For production testing laser diodes after they have been packaged in
temperature controlled modules, Keithley offers the Laser Diode LIV Test
System with increased 28-bit core measurement resolution, allowing for
more detailed characterization. This flexible system combines all the DC
measurement capabilities required to test these modules with tight temperature control over the DUT in a modular instrument package. Configured
from proven Keithley instrumentation, the basic configuration can be easily
modified to add new measurement functions as new testing needs evolve.
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Multi-channel pulsed
Side Text
test of laser diodes
physics of the connections to the device. Keithley’s optoelectronics applications engineers have addressed these issues by studying and documenting
the optimum cable configuration to en­hance measurement accuracy with
extremely fast pulses. Figure 3 illustrates the results of a typical pulse LIV
sweep test with the Model 2520. In this test, a 100-point pulsed LIV sweep
using a 1µs pulse width, at 1% duty cycle, was completed in just 110ms
(including data transfer time), several orders of magnitude faster than
existing, semi-custom test systems.
A
G R E A T E R
M E A S U R E
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C O N F I D E N C E
323
2520
Pulsed Laser Diode Test System
LASER DIODE PULSE OR DC CURRENT SOURCE SPECIFICATIONS
Model
Model
2520
Side
specifications
specifications
Text
DRIVE CURRENT
OFF CURRENT4
Source
Range
Programming
Resolution
Approx.
Electrical
Resolution
Accuracy1, 6
±(%rdg. + mA) 2, 3
RMS Noise
(typical)
(1kHz–20MHz)
0–500 mA
10 µA
8 µA
0.2 + 0.45
0–1.0 A DC
0–5.0 A Pulse
100 µA
80 µA
0.2 + 4.5
TEMPERATURE COEFFICIENT (0°–18°C & 28°–50°C): ±(0.15 × accuracy specification)/°C.
PULSE ON TIME19: 500ns to 5ms, 100ns programming resolution.
PULSE OFF TIME19: 20µs to 500ms, 10µs programming resolution.
PULSE DUTY CYCLE19, 20, 21: 0 to 99.6% for ≤1.0A; 0 to 4% for >1.0A.
VOLTAGE COMPLIANCE: 3V to 10V, 10mV programming resolution5.
POLARITY: 1 quadrant source, polarity reversal available through internal relay inversion.
OUTPUT OFF: <200mW short across laser diode; measured at Remote Test Head connector.
Accuracy1
±(%rdg. + mA)
70 µA
0–15 mA
1 µA
7 nA typ.
0.2 + 0.45
800 µA
0–150 mA
10 µA
70 nA typ.
0.2 + 4.5
Load
7
Range
Minimum
Resolution
Accuracy
±(%rdg. + volts)1, 12
RMS Noise
(typical)13
5.00 V
0.33 mV
0.3% + 6.5 mV
60 µV
10.00 V
0.66 mV
0.3% + 8 mV
120 µV
10.00 mA
20.00
mA
50.00
mA
100.00 mA
DC Input
Impedance
Accuracy
RMS Noise
±(%rdg. + current)1, 2 (typical) 3
0.7 µA
< 10 W
0.3% + 20 µA
90 nA
1.4 µA
< 6 W
0.3% + 65 µA
180 nA
3.4 µA
< 3 W
0.3% + 90 µA
420 nA
6.8 µA
<2.5 W
0.3% + 175 µA
840 nA
TEMPERATURE COEFFICIENT (0°–18°C & 28°–50°C): ±(0.15 × accuracy specification)/°C.
INPUT PROTECTION: The input is protected against shorting to the associated channel’s internal
bias supply. The input is protected for shorts to external supplies up to 20V for up to 1 second
with no damage, although calibration may be affected.
Number of
Source Points17
1
10 18
100 18
1000 18
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To
Memory
5.3
9.5
48
431
Typical
Max.
10 W 1⁄4 Watt
Fast
1.0%
55 ns
80 ns
500 mA
10 W 1⁄4 Watt
Slow
0.1%
1 µs
1.3 µs
5.00 A
1.5 W 1 Watt
Fast
1.0%
100 ns
130 ns
5.00 A
1.5 W 1 Watt
Slow
0.1%
1 µs
1.3 µs
SYSTEM SPEEDS
Reading Rates (ms)15, 16
Rise/Fall Time6, 8, 9, 10
DC FLOATING VOLTAGE: User may float common ground up to ±10VDC from chassis
ground.
COMMON MODE ISOLATION: >109W.
OVERRANGE: 105% of range on all measurements and voltage compliance.
SOURCE OUTPUT MODES:
Fixed DC Level
Fixed Pulse Level
DC Sweep (linear, log, and list)
Pulse Sweep (linear, log, and list)
Continuous Pulse (continuous – low jitter)
PROGRAMMABILITY: IEEE-488 (SCPI-1995.0), RS-232, 5 user-definable power-up states plus
factory default and *RST.
DIGITAL INTERFACE:
Safety Interlock: External mechanical contact connector and removable key switch.
Aux. Supply: +5V @ 300mA supply.
Digital I/O: 2 trigger input, 4 TTL/Relay Drive outputs (33V @ 500mA max., diode
clamped).
Trigger Link: 6 programmable trigger input/outputs.
Pulse Trigger Out BNC: +5V, 50W output impedance, output trigger corresponding to
­current source pulse; pulse to trigger delay <100ns. See Figure 3.
MAINS INPUT: 100V to 240V rms, 50–60Hz, 140VA.
EMC: Conforms to European Union Directive 89/336/EEC (EN61326-1).
SAFETY: Conforms to European Union Directive 73/23/EEC (EN61010-1) CAT 1.
VIBRATION: MIL-PRF-28800F Class 3, Random.
WARM-UP: 1 hour to rated accuracy.
DIMENSIONS, WEIGHT:
Main Chassis, bench configuration (with handle & feet): 105mm high × 238mm wide
× 416mm deep (41⁄8 in. × 93⁄8 in. × 163⁄8 in.). 2.67kg (5.90 lbs).
Remote Test Head: 95mm high × 178mm deep (with interlock key installed) × 216mm
wide (3½ in. × 7 in. × 8½ in.). 1.23kg (2.70 lbs).
ENVIRONMENT:
Operating: 0°–50°C, 70% R.H. up to 35°C. Derate 3% R.H./°C, 35°–50°C.
Storage: –25° to 65°C.
PHOTODIODE CURRENT MEASURE SPECIFICATIONS
(each channel)
Minimum
Resolution4
Pulse
Overshoot
Max.6, 8, 9
GENERAL
RANGE: 0 to ±20VDC.
PROGRAMMING RESOLUTION: 10mV.
ACCURACY: ±(1% + 50mV).
CURRENT: 160mA max. with V-Bias shorted to I-Measure.
RMS NOISE (1kHz to 5MHz): 1mV typical.
Range
Pulse
Mode
500 mA
LASER DIODE VOLTAGE MEASURE SPECIFICATIONS
PHOTODIODE VOLTAGE BIAS SOURCE SPECIFICATIONS (each
channel)
OPTOELECTRONICS TEST
Approx.
Electrical
Resolution
Setting and
Range
TEMPERATURE COEFFICIENT (0°–18°C & 28°–50°C): ±(0.15 × accuracy specification)/°C.
MAX. LEAD RESOLUTION: 100W for rated accuracy.
INPUT IMPEDANCE: 2MW differential, 1MW from each input to common.
Input bias current ±7.5µA max.
324
Range
Programming
Resolution
To
GPIB
6.8
18
120
1170
A
G R E A T E R
M E A S U R E
O F
C O N F I D E N C E
2520
Pulsed Laser Diode Test System
0.6
Full Pulse
0.5
0.4
0.51
0.505
Expanded Pulse Top
Current
0.3
(A)
Current
(A)
0.5
0.2
0.495
0.1
0.49
0
0
5
1. 1 year, 23°C ±5°C.
2.If Duty Cycle · I exceeds 0.2, accuracy specifications must be derated with an additional error term as follows:
500mA Range: ±0.1% rdg. · D · I
5A Range:
±0.3% rdg. · D · I
where:
I = current setting
D = duty cycle
This derating must also be applied for a period equal to the time that D · I was ≥0.2.
3. Not including overshoot and setting time.
4. Pulse mode only.
5. Output: 500mA DC on 500mA range and 1A DC on 5A range.
6. Refer to Model 2520 Service Manual for test setup of current accuracy.
7. Figures 1 and 2 are typical pulse outputs into resistive loads.
8.Typical.
9. Per ANSI/IEEE Std 181-1977.
10.Per ANSI/IEEE Std 181-1977 10% to 90%.
11.DC accuracy ±700mV @ output terminal. 0.2W typical output impedance.
12.At DC, 10µs measurement pulse width, filter off.
13.Standard deviation of 10,000 readings with 10µs pulse width, filter off, with I source set to 0A DC.
14.The A/D converter has 14 bit resolution. The useful resolution is improved by reading averaging. The useful
­resolution is:
0.515
10
15
Time (µs)
0.485
25
20
Figure 1
Pulse Waveform Flatness - 5A into 2 Ohms
6
Full Pulse
5
5.02
Expanded Pulse Top
5
2
4.98
1
4.96
0
5
10
15
Time (µs)
20
Range
·
214
1
Pulse Width (ns) – 400ns
· Averaging Filter Setting
100ns
15.Excluding total programmed (Pulse ON time + Pulse OFF time).
16.Front panel off, calc off, filter off, duty cycle <10%, binary communications.
17.Returning 1 voltage and 2 current measurements for each source point.
18.Sweep mode.
19.Valid for both continuous pulse and sweep modes.
20.Shown is the Power Distribution % based on current settings.
21.Timing Cycle (pw⁄(pw + pd)): 4% max.
5.04
4
Current
3
(A)
0
Useful Resolution =
5.06
Current
(A)
Model
2520
specifications
Model
Side
specifications
Text
Notes
Pulse Waveform Flatness - 500mA into 20 Ohms
4.94
25
Figure 2
Pulse Output/Trigger Output Relationship
6
Trigger
5
4
Volts
3
2
1
0
Pulse
-1
-2
-1.00E-06
-5.00E-07
0.00E+00
5.00E-07
1.00E-06
1.50E-06
OPTOELECTRONICS TEST
Time
Figure 3
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Simplifies pulsed measurements
Side Text
of optical power
2520INT
The Model 2520INT Integrating Sphere is designed to optimize the
Model 2520 Pulsed Laser Diode Test System’s optical power measurement
capabilities. It allows the testing of devices with pulse widths as short as
500ns. The short pulses of the Model 2520 combined with the speed of the
Model 2520INT make them ideal for measuring the optical power of laser
diodes at the bar or chip level, before these devices are integrated into
temperature-controlled modules. When ­connected to the Model 2520 via a
low noise triax cable, the Model 2520INT allows the Model 2520 to make
direct, high accuracy measurements of a laser diode’s optical power. The
results are expressed in m
­ illiwatts.
Designed Specifically for Pulsed Laser Diode Testing
Keithley developed the Model 2520INT to address the challenges specific
to pulse testing laser diodes, which include short pulse periods and fast
rise times. For example, when testing laser diodes in pulse mode, the optical head used must provide a response that’s fast enough to measure light
pulses as short as 500ns. Many optical power detectors are hampered by
long rise times, so they can only measure a portion of the laser diode’s
light output. Even when using a “fast” detector, many detectors are not
good for analog signal measurement. By linking the Model 2520 with the
optimum combination of sphere and detector c­ haracteristics, Keithley
provides the low-level sensitivity needed to ensure accurate pulse measurements.
• Optimized for laser diode pulse
testing
• Suitable for production and
laboratory environments
• Built-in germanium detector
• Works seamlessly with the
Model 2520 Pulsed Laser Diode
Test System
Easier Laser Diode Power Measurements
An integrating sphere is inherently insensitive to variations in the beam
profile produced by a device under test (DUT). The Model 2520INT’s
interior is highly reflective Spectralon, which scatters, reflects, and d­ iffuses the source beam the
DUT produces. This spreads the light from the DUT uniformly over the sphere’s interior surface with
minimal absorption loss. The detector, which reads the amount of optical power produced by the
DUT, is mounted on the interior surface. Due to the multiple diffuse reflections within the sphere,
the amount of optical radiation that strikes the detector is the same as that which falls on any other
point on the sphere’s interior. To convert the attenuated signal measured by the detector into an
accurate optical power measurement, the sphere and detector are calibrated as a unit.
Simplifies Beam Alignment
In a typical laser diode manufacturing line, the laser diode is not coupled to an optical fiber until
the final stages of the packaging process. Therefore, any pulse testing performed on a laser diode at
the bar- or chip-level would require a difficult
and time-consuming beam alignment process in
APPLICATIONS
order to focus all of the diode’s output on the
optical detector.
Bar- or chip-level LIV production
testing of:
OPTOELECTRONICS TEST
To ensure acceptance of the complete beam with
maximum divergence angles, the sphere can be
located up to 3 millimeters from the DUT, positioned so the diode’s light output enters the
1⁄4 -inch port on the sphere’s side. Any light that
enters the sphere is captured in the measurement taken by the Model 2520.
• 980 or 1480 EDFA pump lasers
• Raman amplifiers
• Telecommunication laser diodes
• High power telecommunication
VCSELs
Accessories Required
2520
7078-TRX
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Integrating Sphere for
Pulsed Measurements
A
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M E A S U R E
O F
Pulsed Laser Diode Test System
Low Noise Triax Cable
C O N F I D E N C E
Ordering Information
2520INT-1-Ge
1 inch Integrating
Sphere with
Germanium Detector
2520/KIT1
Pulsed Laser Diode
Measurement
Package (Includes
2520, 2520INT, and
3-foot triax cable)
Accessories Supplied
Quick Start Guide, calibration
data (supplied as a printed
chart and in CSV format on
a floppy diskette), base and
1/4–20 post for mounting
Integrating Sphere for
Pulsed Measurements
Attenuation of Laser Diode Output
Detectors usually have a maximum power limit of a few milliwatts before the detector is over-­
saturated. The Model 2520INT Integrating Sphere’s highly reflective Spectralon interior surface eliminates the problem of detector saturation. This coating reflects and diffuses the light output from the
DUT uniformly over the interior surface of the sphere, which inherently attenuates the level of power
read by the built-in detector. The power level at any point on the sphere’s interior surface is far less
than the power level of a beam that falls directly on the detector. This allows testing much higher
power devices without risking detector damage. The Model 2520INT’s design attenuates the power
output of a laser diode by approximately 100:1.
Optimized for Telecommunications Wavelengths
The Model 2520INT’s germanium detector is capable of detecting wavelengths from 800–1700nm.
The detector and the sphere are calibrated as a unit in 10nm increments at wavelengths that are of
particular interest for laser diode testing (950–1010nm and 1280–1620nm). Calibration constants are
provided in printed form as well as in CSV format on a floppy diskette to simplify programming them
into a test system. When combined with the Model 2520INT, the Model 2520 Pulsed Laser Diode Test
system is capable of measuring power ranging from 14.5mW to 7W, depending on the wavelength
(see the specifications for power ranges by wavelengths of interest).
Fiber Tap for Additional Measurements
The Model 2520INT offers production test engineers the flexibility to decrease overall testing time
by ­supporting multiple optical measurements simultaneously. An additional port on the sphere is
compatible with an SMA connector; together, the port and fiber tap can be used to output a fraction
of the measured light to an external instrument (such as a spectrometer) via a multimode fiber for
additional optical ­measurements.
Eliminates Back Reflections
During testing, the stability of a laser diode can be significantly affected by back reflections from
objects in the optical path. The geometry of the Model 2520INT and the diffusing properties of its
reflective interior help prevent back reflection and ensure greater device stability during testing.
Production or Laboratory
Environments
A slight curvature on the face of the sphere
makes Model 2520INT easier to integrate into
an automated test system. This curvature allows
additional room to connect the sphere to the
DUT electrically and ­simplifies integration with
other system components.
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2520INT
Probe Tip
VCSEL Wafer
A slight curvature on the face of the sphere allows
A slight
curvature
thethe
face
the sphere
additional
room to on
connect
DUTof
electrically
in
closeadditional
quarters, suchroom
as in wafer
probing. the DUT
allows
to connect
electrically in close quarters, such as in wafer
probing.
M E A S U R E
OPTOELECTRONICS TEST
The Model 2520INT is designed with four strategically located mounting holes for flexible
mounting on laboratory tables or in automated
test fixtures. Two of the holes are sized to
accommodate metric fixtures, while the other
two are designed for use with English fixtures.
The Model 2520INT comes with a 1/4–20 base
and post.
Simplifies pulsed measurements
Side Text
of optical power
2520INT
O F
C O N F I D E N C E
327
2520INT
Integrating Sphere for
Pulsed Measurements
Specifications
General
Input Port Diameter: 0.25 in (6.35mm).
Recommended Calibration Cycle: 1 year.
Operating Temperature: 0°–50°C.
Storage Temperature: –25°C–65°C.
Dimensions 8: 60.0mm long × 86.4mm high × 45.7mm deep (2.36 in × 3.40 in × 1.80 in).
Weight 8: 0.15kg (0.33 lbs).
Full Acceptance Angle1: 90° vertical, 50° horizontal (max.).
90° Full Angle
Indicator
Triax
Connector
1
2
3
4
50° Full Angle
Indicator
5
6
SMA
Connector
7
8
Frontal View of Integrating Sphere Showing Full Acceptance Angle
Indicators
Maximum distance from input port to accept at full maximum acceptance angle: 3.1mm (0.12 in).
Calibration performed at 10nm wavelength intervals.
Based on detector being linear to up to 25mA photocurrent and on a signal to noise ratio (SNR) ≥ 100:1.
Calibration of the 2520INT is performed with an open fiber tap port. The power measurement will increase by
approximately 1% with an SMA patch cord attached to the port.
Based on resolution of Model 2520 at 10mA (lowest) current measurement range.
This configuration MUST have a NEGATIVE (reverse) bias voltage applied. If a positive (forward) bias is
applied, the detector (photodiode) will become damaged.
Use of single mode fiber is not recommended.
Only for integrating head, does not include post and base.
Operating Wavelength Range: 800–1700nm.
Continuous Wave (CW) Calibration Wavelength Range2: 950–1010nm and 1280–
1620nm.
Wavelength (nm)
980
1310
1480
1550
Measurable Optical
Power Range 3
29mW–7W
17mW–4W
14.5mW–3.5W
13.5mW–3W
Typical
Responsivity 4
(mA/W)
3.5
6.0
7.0
7.5
0.0075
0.0065
Resolution
(mW)
0.2
0.1
0.1
0.1
Responsivity, A/W
Model
Model
2520INT
Side
specifications
Text
specifications
Notes
5
0.0045
0.0035
0.0025
Maximum Reverse Bias: 5V (recommended).
Dark Current at Max Reverse Bias: 4µA (typ.); 10µA (max.).
Photodiode Electrical Connections on 3 Lug Triax 6:
Center Conductor
(Cathode)
0.0055
950
1050
1150
1250
1350
Wavelength, nm
Typical responsivity of the Model 2520INT
Inner Shield
(Anode)
Photodiode
OPTOELECTRONICS TEST
Outermost Shield (not connected)
(isolated from chassis)
Pulsed Operation: The 2520INT supports the pulse capabilities of the 2520 Pulsed Laser
Diode Test System.
Fiber Tap Port: Connector Type: SMA. Numerical Aperature (NA): 0.22 (typ.).
Multi-Mode Patch Cord
Core Diameter 7 (µm)
400
100
62.5
50
Typical
Attenuation (dB)
39.5
53
58.2
63
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1450
1550
1650
Complete DC Test System
with Temperature Control
Keithley’s LIV (light-current-voltage) Test System
Kit is designed to help manufacturers of laser
diode modules (LDMs) keep pace with production demands by allowing them to boost yield
and throughput. The LIV test system combines
all the DC measurement capabilities required to
test these modules with optical power measurement and tight temperature control over the
device under test in an integrated instrument
package. The LIV test system is configured from
proven Keithley instrumentation; the basic
configuration can be easily modified to add
new meas­urement functions or to allow for new
­connections.
Tight Integration Ensures
Higher Test Speeds
Shown: S25-22224 fully assembled and installed in optional 8000-10 equipment
The LIV test system allows for fast, easy integrarack (laser diode module not included)
tion and high test speeds because all the building blocks come from the same supplier. All
• Programmable LIV test system for
newer Keithley instruments include the Trigger Link feature and digital I/O lines, as well as standard
laser diode modules
IEEE-488 (GPIB) and RS-232 interfaces, to speed and simplify system integration and control. The
Trigger Link feature combines independent software selectable trigger lines on a single connector for
• Sweep and measure 400 points
simple, direct control over all instruments in a system without the need for constant traffic over the
in <8s
GPIB. This feature is particularly useful for reducing total test time if the test involves a sweep. The
• Very low noise current source
digital I/O lines simplify external handler control and binning operations.
(50µA) for laser diode drive
• Up to 5A laser diode drive current
• Measures optical power directly
• 1fA resolution for dark current
measurements
• Fully digital P-I-D loop for
temperature control
• ±0.005°C temperature stability,
±0.001°C setpoint resolution
• Trigger Link, source memory,
and buffer memory support
automatic test sequencing, which
greatly reduces GPIB bus traffic
to improve test throughput
• Expandable and flexible
for future requirements
Source memory and buffer memory, provided by Models 2400-LV, 2420, 2440, and 2502, enable
elimination of GPIB traffic during sweep testing. Source memory is a built-in “programmable test
sequencer” for configuring up to 100 different tests. The buffer memory stores data that can be
downloaded to the PC via the GPIB after an LIV test sweep is complete. Source memory, buffer
memory, and Trigger Link work in concert to form an autonomous test system—all it takes to begin
the test sequence is a “start of test” command from the PC. Benchmark testing has demonstrated that
these features allow the system to complete a 400-point LIV test sweep with data transfer to the PC
in less than eight seconds.
Easy to Program, Easy to Use
Each kit comes complete with the necessary cables and hardware to use the system. Having all the
instrumentation supplied by the same vendor simplifies system programming and improves ease of
use. All instruments in the standard system respond to the same SCPI command structure. LabVIEW®
and Visual Instrument drivers and demonstration software are also available to simplify application
development.
Flexible System Configuration Options
In addition to the standard system configurations, LIV test systems can be customized to accommodate virtually any test sequence or setup requirement. Adding new capabilities or expanding existing
ones is as simple as adding a new Keithley instrument or switch system. For example, to add isola­
tion resistance measurements, just include any of Keithley’s Series 2000 Digital Multi­meters in the
­configuration.
To accommodate multiple pin-out schemes, choose a Series 7000 Switch Mainframe and plug in one
or more switch cards, such as the Model 7012 4×10 Matrix Card or the Model 7053 High Current
Scanner Card for switching up to 5A. Automated switching makes it simple to accommodate future
pin-out configuration changes.
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Complete test solutionsSide
for individual
Text
application needs
Laser Diode Test System Kit
A
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OPTOELECTRONICS TEST
System 25
C O N F I D E N C E
329
System 25
Laser Diode LIV Test System Kit
OPTOELECTRONICS TEST
Complete test solutionsSide
for individual
Text
application needs
A custom configuration and ordering guide is available to simplify selecting
all the critical items needed to complete a system.
Single Vendor Solution
In addition to the assurance of hardware and software compatibility,
­systems integrators can be confident they’ll get all the technical support
they need to complete and maintain their systems from a single source.
Keithley’s applications engineers can help systems integrators optimize the
performance of each instrument in the system to ensure high speed and
accuracy from the system as a whole.
• Model 2500INT Integrating Sphere. This accessory for the Model 2502
accepts direct optical input and provides for accurate L measurement
without being sensitive to polarization mode or beam profile at the end
of the fiber. The integrating sphere is available with a silicon, germanium, or cooled indium gallium arsenide detector to ensure accurate
optical power measurements at any wavelength.
High Accuracy Building Blocks
The standard LIV test system provides a fast, flexible solution for testing
LDMs by combining the functions of several high speed, high accuracy
Keithley instruments:
• Model 854x. The 854x Laser Diode Mount Series makes it easier than
ever to configure a complete laser diode LIV test system for continuous
wave test applications. These fixtures provide highly stable temperature
control for all telecommunications laser diodes. They offer an easy-touse platform for testing laser diodes used in telecommunications. They
are designed to speed and simplify setting up test systems for all laser
diode/photodiode/thermoelectric cooler/thermistor configurations.
• Model 2400-LV, 2420, or 2440 High Current SourceMeter® instrument. During LIV testing, the SourceMeter instrument provides
a current sweep to drive the laser diode. It also synchronizes the
measurements made by other instruments in the system. The Models
2400-LV, 2420, and 2440 SourceMeter instruments are part of Keithley’s
SourceMeter family and were developed specifically for test applications
that demand tightly coupled precision voltage and current sourcing and
measurement. Selecting the instrument’s high current range eliminates
the potential for range change glitches if currents higher than 1A are
needed during the LIV sweep. The Model 2420 offers drive current of
up to 3A. The Model 2440 offers up to 5A of drive current for demanding pump laser control.
For additional information on any of the building blocks of the LIV test
system, refer to the data sheet for that instrument.
• Model 2502 Dual Photodiode Meter. The Model 2502 measures the
current flow in the back facet photo detector and combines with the
Model 2500INT Integrating Sphere to directly measure optical power.
Both optical power measurement channels are fully independent. The
measurement timing c­ ircuitry is shared between both channels to
provide simultaneous measurements to optimize LIV ­performance. Each
channel has eight measurement ranges and provides a resolution high
enough to measure dark currents of the photodiode. The isolated bias
sources provide up to 100V of bias. The Model 2502 has a high speed
analog output that allows the LIV system to be combined with a fiber
alignment system.
• Model 2510-AT TEC SourceMeter instrument. The Model 2510-AT
is a 50W bipolar instrument that controls the operation of an LDM’s
Thermo-Electric Cooler or TEC (sometimes called a “Peltier device”)
during LIV testing. During testing, the Model 2510-AT meas­ures the
internal temperature of the LDM from any of a variety of temperature
sensors, then drives power through the TEC in order to maintain the
LDM’s temperature at the desired setpoint.
A demonstration software package, written in Visual Basic, is
available with the LIV test system to give programmers a head start
on creating their own applications. Using the demon­stra­tion package,
users can set a variety of test parameters, including NPLC (integration
time), Source Delay (settling time before measurement), Start Current,
Stop Current, and Step Current. These parameters allow users to
define the current sweep range and make speed and accuracy tradeoffs by adjust­ing Source Delay and NPLC. The result­ing data can be
analyzed to deter­mine threshold current and kink statis­tics. The total
test time includes the instrument setup, LIV sweep, and data transfer
times (but not the ­computation times).
The Model 2510-AT’s software-based, fully digital P-I-D (proportionalintegral-differential) control provides excellent temperature stability.
This high stability allows for very fine control over the output wavelength and over the optical power of the LDM during testing. Another
Model 2510-AT can be added to include ambient fixture control, if the
test will be done under a variety of ambient conditions. The instrument
includes a low-level TEC resistance meas­ure­ment function to check
TECs for mechanical damage during m
­ odule ­assembly.
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The Model 2510-AT offers autotuning capability. P, I, and D (proportional, integral, and derivative) ­values for closed loop ­temperature control are determined by the instrument using a modified Zeigler-Nichols
algorithm. This eliminates the need for users to experiment by inputting
various P, I, and D coefficients repeatedly in order to determine the
optimal values.
A
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C O N F I D E N C E
Laser Diode LIV Test System Kit
Ordering Information
Temperature Control
General Purpose
Transmitter/Pump
Pump Laser
Source/
Measure
Laser Diode Mounts
0
None
2
8542
4
8544
4t 8544-TEC
Peltier
Measure
2400-LV,
2420, or
2440
Temperature Control
0
None
1
2510-AT
Single Temp. Control
2
2510-AT/2510-AT Dual Temp. Control
Integrating Spheres
00 None
21 2500INT-2-SI
22 2500INT-2-GE
23 2500INT-2-IGAC
Thermistor
2502
Fiber
Computer
2˝ Sphere, Silicon
2˝ Sphere, Germanium
2˝ Sphere, Cooled InGaAs
GPIB
2500INT
Figure 1. The standard LIV test system is designed for applications
that require the highest measurement accuracy. The Model 2420
SourceMeter instrument drives the laser diode, sweeping the drive
current from 0A up to 3A in programmable steps. At each step
in the sweep, the Model 2420 records the current and voltage
measurements, while the Model 2502 measures and records the
current flow in the photodiodes. When the sweep is complete, the
raw measurement data from the Model 2420 and the Model 2502 is
uploaded to the PC for analysis. The LIV Demo Software can calculate
first and second derivatives of the back facet monitor diode or the
external photo detector.
14-Pin DIL Mount
14-Pin Butterfly Mount
14-Pin Butterfly w/TEC Control
Select the instrument and accesory for your application.
Review the detailed specifications of each instrument
in individual catalog sections.
Accessories Included in Each Option
Source/Measure
Includes:
2400-LV, 2420, or 2440 SourceMeter Instrument
2502 Photodiode Meter
(2) GPIB Interface Cables
Trigger Link Cable
Integrating Sphere Cable and adapter (Triax, 6172 adapter)
DUT Cables (terminated in Alligator clips)
Rackmount Conversion Kit
Accessories Available
Cables
7007-1
7007-2
Temperature Control
Includes:
2510-AT SourceMeter Instrument(s)
GPIB Interface Cable(s)
DUT Cables
Rackmount Conversion Kit
Integrating
Includes:
Sphere
2500INT Integrating Sphere
½˝ open input port
Post Stand
Laser Diode
Includes:
Mount
854x Laser Diode Mount
Easy Connect Multi Terminated Laser Diode Cables
Easy Connect Multi Terminated Temperature Cables
Double Shielded GPIB Cable, 1m (3.3 ft.)
Double Shielded GPIB Cable, 2m (6.6 ft.)
Fiber Adapters
(System kit has a ½˝ input port. For fiber input add adapter below.)
2500INT-FC/APC FC/APC Fiber Adapter to Integrating Sphere
2500INT-FC/PC FC/PC Fiber Adapter to Integrating Sphere
2500INT-SMA SMA Fiber Adapter to Integrating Sphere
Cabinets
(System kit is supplied with all necessary rack mount hardware. Purchase appropriate cabinet and
assembly services separately.)
8000-10
Equipment Cabinet 10˝ high (holds 4 instruments)
8000-14A
Equipment Cabinet 14˝ high
8000-17A
Equipment Cabinet 17.5˝ high
GPIB Cards
(GPIB communication required for complete LIV capabilities.)
KPCI-488LPA
IEEE-488 Interface/Controller for the PCI Bus
KUSB-488B
IEEE-488 USB-to-GPIB Adapter for USB Port
Custom Systems
Custom systems are available. Contact your local Keithley sales person.
Assembly Services
The S25 Systems are not assembled. If you would like assembly service, contact your local
Keithley salesperson.
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System 25 Laser Diode
SideLIV System
Text
specifications
2510-AT
S25Source/Measure
0
2400-LV/2502
2
2420/2502
4
2440/2502
Trigger Link
A
G R E A T E R
M E A S U R E
O F
OPTOELECTRONICS TEST
System 25
C O N F I D E N C E
331
Tightly coupled source and measure
Side Textfor active component testing
2400-LV, 2400-C,
2420, 2420-C,
2440, 2440-C
The Model 2420 offers a tighter accuracy specification that allows for precise control of transmitter laser
devices. In addition to higher accuracy, the Model 2420
offers a drive current of up to 3A for devices that need
drive currents greater than 1A, such as pump lasers used
in EDFA a­ mplifiers.
• Designed for production
testing of VCSELs, transmitter,
high power pump lasers, and
other high current electronic
components
The Model 2440 5A SourceMeter Instrument further broadens the capabilities offered by the popular
SourceMeter line. The dynamic range and functionality of the Model 2440 makes it ideal for applications such as testing high power pump lasers for use in optical amplifiers, laser bar tests, and testing
other higher power components. Manufacturers of Raman pump laser modules and optical amplifiers
will find it invaluable for a wide range of design and production test applications.
• Key building block for
programmable LIV test system
for laser diode modules
A Keithley SourceMeter instrument provides a complete, economical, high throughput solution for
component production testing, all in one compact, half-rack box. It combines source, measure, and
control capabilities in a form factor that’s unique to the industry. The SourceMeter is also suitable for
making a wide range of low power DC measurements, including resistance at a specified current or
voltage, breakdown voltage, leakage current, and insulation resistance.
• Very low noise current source
(50µA) for laser diode drive
• Up to 5A laser diode drive
current
• Reduced GPIB bus traffic
improves test throughput
• Expandable and flexible for
future requirements
• Built-in comparator for fast
pass/fail testing
• Digital I/O handler interface
OPTOELECTRONICS TEST
®
The SourceMeter family was developed specifically for
test applications that demand tightly coupled ­precision
voltage and current sourcing and concurrent measurement, including source read back. This family of instruments can be easily programmed to drive laser diodes
throughout the characterization process. Any of them
can also be programmed to act as a synchronization
­controller to ensure simultaneous measurements during
the test sequence. Selecting a fixed current range eliminates the potential for range offsets that appear as kinks
during the LIV sweep testing. The Model 2400-LV offers a
drive ­current of up to 1A, ideal for testing VCSEL devices.
• Trigger Link, Source Memory,
and buffer memory support
automatic test sequencing
• 1000 readings/second at
4½ digits
• Optional contact check function
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332
SourceMeter Instruments for
Optoelectronic I-V Testing
Single Box Solution
By linking source and measurement circuitry in a single unit, a SourceMeter instrument offers a variety of advantages over systems configured with separate source and measurement instruments. For
example, it minimizes the time required for test station development, setup, and maintenance, while
lowering the overall cost of system ownership. It simplifies the test ­process itself by eliminating many
of the complex synchronization and connection issues associated with using multiple instruments. Its
compact, half-rack size conserves “real estate” in the test rack or bench.
ACCESSORIES AVAILABLE
Laser Diode Mounts
8542
Dual In-Line Telecom Laser Diode Mount Bundle
8544
Butterfly Telecom Laser Diode Mount Bundle
8544-TEC
Butterfly Telecom Laser Diode Mount Bundle
with TEC, thermistor, and AD592CN temperature
sensor
Communication Interface
KPCI-488LPA IEEE-488 Interface/Controller for the PCI Bus
KUSB-488B
IEEE-488 USB-to-GPIB Adapter for USB Port
SWITCHING
7001
7002
7053
HARDWARE
Two-Slot Switch System
Ten-Slot Switch System
High-Current Switch Card
A
G R E A T E R
TEST LEADS AND PROBES
5806
Kelvin Clip Lead Set
CABLES/ADAPTERS
2499-DIGIO Digital I/O Expansion Assembly
7007-1
Shielded GPIB Cable, 1m (3.3 ft)
7007-2
Shielded GPIB Cable, 2m (6.6 ft)
7009-5
RS-232 Cable
8501-1
Trigger Link Cable, 1m (3.3 ft)
8501-2
Trigger Link Cable, 2m (6.6 ft)
8502
Trigger Link Adapter Box
RACK MOUNT KITS
4288-1
Single Fixed Rack Mount Kit
4288-2
Dual Fixed Rack Mount Kit
M E A S U R E
O F
C O N F I D E N C E
• Source Memory List test sequencer with conditional branching
Measurements up to 20V and 1A, 20W
Power Output
• Handler/prober interface
2400-CGeneral-Purpose
SourceMeter
• Trigger Link compatibility with switching hardware and other instruments from Keithley
• High speed comparator, pass/fail limits, mathematical scaling
Contact Check, Measurements up to
200V and 1A, 20W Power Output
• Deep memory buffer
2420High-Current
SourceMeter
The SourceMeter instruments also offer standard RS-232 and GPIB interfaces for integration with a
PC. Adding one of Keithley’s versatile switch systems enables fast, synchronized multipoint testing.
Measurements up to 60V and 3A, 60W
Power Output
Testing Optoelectronic Components
Use a SourceMeter instrument to measure a component’s electrical performance characteristics and
to drive laser diodes and other components.
2420-CHigh-Current
SourceMeter
Contact Check, Measurements up to 60V
and 3A, 60W Power Output
5A SourceMeter
Measurements up to 40V and 5A, 50W
Power Output
5A SourceMeter
Contact Check, Measurements up to 40V
and 5A, 50W Power Output
Accessories Supplied
Test Leads, User’s Manual, Service
Manual, and LabVIEW® Drivers
Types of Optoelectronic Components
• Laser diodes
• Laser diode modules
• Photodetectots
• Light-emitting diodes (LEDs)
• Photovoltaic cells
Model
Description
Power Output
Voltage Range
Current Range
Ohms Range
2400-LV/2400-C
General Purpose
20 W
±1 µV to ±20 V
±50 pA to ±1.05 A
<0.2 W to >200 W
Optoelectronic components.
VCSELs.
Applications
Model 2400-LV
SourceMeter
Instrument
Model 2420
3A SourceMeter
Instrument
I
+3A
+100mA
+20V
V
–60V
–20V
2420/2420-C
3A
60 W
±1 µV to ±63 V
±500 pA to ±3.15 A
<0.2 W to >200 MW
Transmitter modules.
EDFA pumps.
+5A
+3A
+1A
+100mA
+100mA
+60V
–40V
V
–100mA
–10V
+10V
+40V
V
–100mA
–1A
–1A
I
+1A
+20V
–100mA
2440-LV/2440-C
5A
50 W
±1 µV to ±42 V
±500 pA to ±5.25 A
<2.0 W to >200 MW
5A pump laser diodes.
Raman amplifiers.
Model 2440
5A SourceMeter
Instrument
I
+1A
–20V
Typical Tests
• LIV test (laser diodes and LEDs)
• Kink test (laser diode)
• I-V characterization
–1A
= duty cycle limited
–3A
–3A
–5A
The Model 2400-LV is ideal for testing a wide variety
of devices, including diodes, resistors, resistor networks,
active circuit protection devices, and portable batterypowered devices and components.
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Choose the Model 2420 for testing higher power
resistors, thermistors, I DDQ , solar cells, batteries, and
high-current or medium power diodes, including
switching and Schottky diodes.
A
G R E A T E R
The Model 2440’s wide dynamic range is well-suited
for applications such as testing high-power pump lasers
for use in optical amplifiers and laser bar tests, as well
as testing other higher power components.
M E A S U R E
O F
Tightly coupled source and measure
Side Textfor active component testing
2400-LV Low Voltage Model
2400 SourceMeter
2440-C
®
High Throughput to Meet Demanding Production Test Schedules
A SourceMeter instrument’s highly integrated architecture offers significant throughput advantages.
Many features of this family enable them to “take control” of the test process, eliminating additional
system bus traffic and maximizing total throughput. Built-in features that make this possible include:
Ordering Information
2440
SourceMeter Instruments for
Optoelectronic I-V Testing
OPTOELECTRONICS TEST
2400-LV, 2400-C,
2420, 2420-C,
2440, 2440-C
C O N F I D E N C E
333
2400-LV, 2400-C,
2420, 2420-C,
2440, 2440-C
SourceMeter Instruments for
Optoelectronic I-V Testing
®
Faster, Easier, and More Efficient Testing
and Automation
Optional Contact Check
The Contact Check option available on all Series 2400 SourceMeter instruments allows quick verification of a good connection to the DUT before
functional testing proceeds. This feature helps prevent the loss of precious
test time due to damaged, corroded, or otherwise faulty contacts in a test
fixture. The innovative contact check design completes the verification
and notification process in less than 350µs; comparable capabilities in
other test equipment can require up to 5ms to perform the same function.
Contact check failure is indicated on the instrument’s front panel and over
the GPIB bus. The digital I/O interface can also be used to communicate
contact failure to the component handler in automated applications.
2400, Model
2420,Side
2440
specifications
Text
specifications
Coupled Source and Measure Capabilities
The tightly coupled nature of a SourceMeter instrument provides many
advantages over separate instruments. The ability to fit a source and a
meter in a single half-rack enclosure saves valuable rack space and simplifies the remote programming interface. Also, the tight control and a single
GPIB address inherent in a single instrument result in faster test times for
ATE applications due to reduced GPIB traffic.
Standard and Custom Sweeps
SourceMeter instruments provide sweep solutions that greatly accelerate
testing with automation hooks for additional throughput improvement.
SourceMeter Instrument Specifications
The following tables summarize the capabilities of the Models 2400-LV, 2420, and 2440.
2400-LV SourceMeter (I-V Measurements)
Current Programming Accuracy
Programming
Range
Resolution
1.00000 µA
50 pA
10.0000 µA
500 pA
100.000 µA
5 nA
1.00000mA
50 nA
10.0000 mA
500 nA
100.000 mA
5 µA
1.00000 A
50 µA
Accuracy (1 Year)
23°C ± 5°C
± (% rdg. + amps)
0.035% + 600 pA
0.033% + 2nA
0.031% + 20nA
0.034% + 200nA
0.045% + 2µA
0.066% + 20µA
0.27 % +900µA
OPTOELECTRONICS TEST
2420 SourceMeter (I-V Measurements)
Current Programming Accuracy
Accuracy (1 Year)
Programming
23°C ± 5°C
Range
Resolution
± (% rdg. + amps)
10.0000 µA
500 pA
0.033% + 2nA
100.000 µA
5 nA
0.031% + 20nA
1.00000mA
50 nA
0.034% + 200nA
10.0000 mA
500 nA
0.045% + 2µA
100.000 mA
5 µA
0.066% + 20µA
1.00000 A
50 µA
0.067% +900µA
3.00000 A
50 µA
0.059% + 2.7mA
2440 SourceMeter (I-V Measurements)
Current Programming Accuracy
Accuracy (1 Year) 3
Programming
23°C ± 5°C
Range
Resolution
± (% rdg. + amps)
10.0000 µA
500 pA
0.033% + 2nA
100.000 µA
5 nA
0.031% + 20nA
1.00000 mA
50 nA
0.034% + 200nA
10.0000 mA
500 nA
0.045% + 2µA
100.000 mA
5 µA
0.066% + 20µA
1.00000 A
50 µA
0.067% +900µA
5.00000 A
50 µA
0.10 % + 5.4mA
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Voltage Measurement Accuracy
Default
Range
Resolution
200.000 mV
1 µV
2.00000 V
10 µV
20.0000 V
100 µV
Input
Resistance
> 10 GW
> 10 GW
> 10 GW
Accuracy (1 Year)
23°C ±5°C
± (% rdg. + volts)
0.01 % +300 µV
0.012% +300 µV
0.015% + 1.5 mV
Voltage Measurement Accuracy
Default
Range
Resolution
200.000 mV
1 µV
2.00000 V
10 µV
20.0000 V
100 µV
60.0000 V
1 mV
Input
Resistance
> 10 GW
> 10 GW
> 10 GW
> 10 GW
Accuracy (1 Year)
23°C ±5°C
± (% rdg. + volts)
0.012% +300 µV
0.012% +300 µV
0.015% + 1 mV
0.015% + 3 mV
Voltage Measurement Accuracy
Default
Range
Resolution
200.000 mV
1 µV
2.00000 V
10 µV
10.0000 V
100 µV
40.0000 V
1 mV
Input
Resistance
> 10 GW
> 10 GW
> 10 GW
> 10 GW
Accuracy (1 Year)
23°C ±5°C
± (% rdg. + volts)
0.012% +300 µV
0.012% +300 µV
0.015% +750 µV
0.015% + 3 mV
A
G R E A T E R
M E A S U R E
O F
C O N F I D E N C E
2502
Dual-Channel Picoammeter for
Photodiode Measurements
Wide Dynamic Measurement Range
The Model 2502 offers current measurement
ranges from 2nA to 20mA in decade steps. This
provides for all photodetector current measurement ranges for testing laser diodes and LEDs in
applications such as LIV testing, LED total radiance measurements, measurements of cross-talk
and insertion loss on optical switches, and many
others. The Model 2502 meets industry testing
requirements for the transmitter as well as pump
laser modules.
• ±100V bias source
• Measure current from 1fA to
20mA
• 1fA current measurement
resolution
• 0–10V analog output for high
resolution optical power
feedback
• 3000-point buffer memory on
each channel allows data transfer
after test completion
• Digital I/O and Trigger Link
for binning and sweep test
operations
• IEEE-488 and RS-232 interfaces
Ordering Information
2502Dual-Channel
Picoammeter
Accessories Supplied
User’s Manual
Services Available
High Accuracy Dark Current Measurements
The Model 2502’s 2nA current measurement range is ideal for measuring dark currents with 1fA
­resolution. Once the level of dark current has been determined, the instrument’s REL function
­automatically subtracts the dark current as an offset so the measured values are more accurate for
optical power measurements.
Voltage Bias Capability
The Model 2502 provides a choice of voltage bias ranges: ±10V or ±100V. This choice gives the ­system
integrator the ability to match the bias range more closely to the type of photodetector being tested,
typically ±10V for large area photodetectors and ±100V for avalanche-type photodetectors. This ability to match the bias to the photodetector ensures improved measurement linearity and accuracy.
Ratio and Delta Measurements
The Model 2502 can provide ratio or delta measurements between the two completely isolated
­channels, such as the ratio of the back facet monitor detector to the fiber-coupled photodetector
at varying levels of input current. These functions can be accessed via the front panel or the
GPIB ­interface. For test setups with multiple detectors, this capability allows for targeted control
­capabilities for the laser diode module.
Interface Options
To speed and simplify system integration and control, the Model 2502 includes the Trigger Link
­feature and digital I/O lines, as well as standard IEEE-488 and RS-232 interfaces. The Trigger Link
­feature combines six independent software selectable trigger lines on a single connector for simple,
direct control over all instruments in a system. This feature is e­ specially useful for reducing total test
time if the test involves a sweep. The Model 2502
can sweep through a series of measurements
based on triggers received from the SourceMeter
Instrument. The digital I/O lines simplify external handler control and binning operations.
For additional information and detailed
specifications, see page 114.
2502-3Y-EW
1-year factory warranty extended to 3 years
from date of shipment
C/2502-3Y-DATA 3 (Z540-1 compliant) calibrations within 3 years
of purchase*
*Not available in all countries
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Model 2502 rear panel
A
G R E A T E R
M E A S U R E
O F
OPTOELECTRONICS TEST
• Dual-channel instrument for
low current measurements
Dual-channel optical
Side power
Text measurement
The Model 2502 combines Keithley’s expertise in
low-level current measurements with high speed
current measurement capabilities. Each channel
of this instrument consists of a voltage source
paired with a high speed picoammeter. Each of
the two channels has an independent picoammeter and voltage source with ­measurements
made simultaneously across both ­channels.
C O N F I D E N C E
335
Enables direct optical power measurement
Side Text in watts with the Model 2502
2500INT
The Model 2500INT Integrating Sphere is the latest addition to
Keithley’s growing line of solutions for LIV (light-current-voltage) testing. When connected via a low noise triax cable to the
Model 2502 Dual Photodiode Meter included in Keithley’s LIV
Test System, the integrating sphere allows the system to make
direct measurements of optical power, with results expressed
in watts. The integrating sphere simplifies production testing of
laser diodes (LDs), light emitting diodes (LEDs), and other optical components by eliminating common optical power measurement problems related to detector alignment, beam profile,
polarization, and back reflection.
Choice of Three Detector Types
The Model 2500INT is available with a silicon (2500INT-2-Si),
­germanium (2500INT-2-Ge), or cooled indium gallium arsenide
(InGaAs) detector (2500INT-2-IGAC), each calibrated with the
sphere. Spheres equipped with cooled indium gallium arsenide detectors include a controller to regulate the detector’s
­temperature.
Unaffected by DUT Beam Profile
Laser diodes can produce non-gaussian beam profiles, which
can lead to inaccurate optical power measurements due to
underfill or overfill of the detector. While a number of methods
are available to correct for underfill and overfill, these methods
can add to the overall inaccuracy of the ­­measure­ment.
• Choose from silicon, germanium,
or cooled indium gallium arsenide
detectors
• Spectralon® sphere interior
ensures high reflectivity
• Part of Keithley’s high through­put
system for production testing of
laser diodes and LEDs
OPTOELECTRONICS TEST
Ordering Information
2500INT-2-Si
Integrating Sphere
with Silicon Detector
2500INT-2-Ge
Integrating Sphere with
Germanium Detector
2500INT-2-IGAC
Integrating Sphere with
Cooled Indium Gallium
Arsenide Detector
Accessories Supplied
Quick Start Guide, Calibration
Chart for each sphere,
TEC Controller (included with
2500INT-2-IGAC)
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Integrating Sphere
In contrast, an integrating sphere is inherently insensitive to beam profiles. The interior of the Model
2500INT integrating sphere has a highly reflective Spectralon surface, which scatters, reflects, and
diffuses the source beam produced by the device under test (DUT). This spreads the light from the
DUT uniformly over the interior surface of the sphere with minimal absorption loss. A detector can
be placed on the interior surface of the sphere, then the sphere/detector combination can be calibrated. The amount of optical radiation striking the detector is the same as any other point on the
sphere interior due to the multiple diffuse reflections within the sphere. Therefore, the calibration
and resulting measurement accuracy are independent of beam profile.
The Model 2500INT’s Spectralon surface offers a variety of other advantages. It is a nearly perfect
­diffuse reflector, exhibiting Lambertian reflectance properties, so it reflects equally in all directions,
regardless of viewing angle. This eliminates the inaccuracies associated with less diffuse materials by distributing the optical radiation more evenly over the interior of the sphere. In addition, a
Spectralon surface offers high reflectance for wavelengths from 250–2500nm, which makes it ideal
for laser diode measurement applications. It is also chemically inert, which helps ensure stable measurements in harsh environments.
Eases Beam Alignment
If an integrating sphere is not used in laser
diode testing, the entire beam from the laser
must shine directly onto the detector in order to
measure optical power accurately. However, it
is difficult to align a laser and detector with the
high degree of precision required, particularly
when the laser is operating outside of the visible
spectrum. With the use of an integrating sphere,
beam alignment is trivial because any light that
enters the sphere will be spread evenly across
its interior surface. Simply stated, it is easier
to direct a laser into a ½-inch port than it is to
direct a laser onto a 5mm detector. The sphere
A
G R E A T E R
M E A S U R E
Applications
Production testing of:
• Laser diode modules
• Chip on submount laser diodes
• Laser diode bars
• LEDs
• Passive optical components
O F
C O N F I D E N C E
2500INT
is insensitive to input beam alignment up to 40° off normal or divergences
up to 40° half-angle.
2510 or
2510-AT
Thermistor
Minimizes Polarization Concerns
The randomizing effects of multiple reflections within Keithley’s integrating sphere minimize beam polarization problems that can affect optical
measurement accuracy when measuring polarized sources. Beam polarization is of particular concern for manufacturers of distributed feedback
lasers (DFBs) and Vertical Cavity Surface Emitting Lasers (VCSELs).
Peltier
2400/
2420
Eliminates Back Reflection
The stability of a laser diode is significantly affected by back reflections
from objects in the optical path. The geometric nature of the integrating
sphere and the diffusing properties of the sphere’s reflective material help
prevent back reflection and ensure greater device stability during testing.
2502
Fiber
Computer
Attenuates High Power Laser Diode Outputs
Detectors have specified maximum power capability, which is typically just
a few milliwatts. By spreading the output power evenly over its interior
surface, an integrating sphere automatically attenuates the power from
the source; therefore, the power level at any point on the sphere surface is
far less than that of a beam that falls directly on the detector. The Model
2500INT sphere is particularly useful for testing high-power laser diodes
because it provides calibrated attenuation of the laser diode output, which
prevents damage to the detector due to the high density of the output or
other problems associated with saturation of the detector.
GPIB
2500INT
The Model 2500INT allows the LIV Test System to measure optical
inputs directly and to display power measurements in watts. Other
instruments in the LIV Test System include the Model 2502 Dual
Photodiode Meter, the Model 2510 TEC SourceMeter® Instrument, and
either the Model 2400 or Model 2420 SourceMeter Instrument. Each
integrating sphere is characterized at the factory and provided with a
calibration constant for every 25 nanometers in the detector’s range.
Prior to testing, the user simply enters the constant in the Model 2502
Dual Photodiode Meter to ensure accurate meas­ure­ments of optical
power for that wavelength.
Silicon
Detector
190–1100 nm
960 nm
Excellent at 960 nm
Wavelength Range
Peak Wavelength (λp)
Sensitivity at Peak Wavelength
Sensitivity at Certain Wavelengths
Visible
***
980 nm
***
1310 nm
N/A
1550 nm
N/A
>1550 nm
N/A
Speed
***
Calibration Accuracy/Stability
Spectral response changes
rapidly with temperature
at wavelengths >1000nm.
Cost
Designed Specifically for Laser Diode Testing
The design of the Model 2500INT Integrating Sphere is optimized for
measuring the optical power of laser diodes. Each sphere is two inches in
diameter with a ½-inch input port suitable for fiber or direct light (as in
chip on submount applications). The port and detector are positioned so
there is no need to use a baffle to prevent the input from shining directly
onto the detector.
Cooled InGaAs
Detector
900–1670 nm
1550 nm
Excellent at 1550 nm
Germanium Detector
800–1800 nm
1550 nm
Good at 1550 nm
N/A
**
**
**
**
*
Spectral response changes
rapidly with temperature and
λ above λp.
$
$$
N/A
**
***
***
***
**
Extremely stable (Spectral response
is stable because λ calibration
is fixed at constant operating
temperatures, i.e., –10°C.)
$$$
Detector Selection Criteria
When choosing the most appropriate detector
for a specific application, consider the following
selection criteria:
• Wavelengths of maximum interest
• Sensitivity at wavelength of ­interest
• Speed
• Cost
• Calibration accuracy/stability
* = Good ** = Better *** = Best N/A = not applicable
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A
G R E A T E R
M E A S U R E
O F
OPTOELECTRONICS TEST
Trigger Link
Enables direct optical power measurement
Side Text in watts with the Model 2502
Integrating Sphere
C O N F I D E N C E
337
2500INT
Integrating Sphere
SPECIFICATIONS
Model
Model
2500INT
Side
specifications
Text
specifications
Typical Reflectance Data for
Spectralon Material
Wavelength (nm)
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
Spectralon
0.991
0.992
0.992
0.991
0.992
0.993
0.992
0.992
0.992
0.991
0.990
0.989
0.986
ACCESSORIES AVAILABLE
Physical, Thermo-Optical, and Electronic Properties of Spectralon Material
Property
Density
Water Permeability
Hardness
Thermal Stability
Coefficient of Linear Expansion
Vacuum Stability
ASTM Test
N/A
D-570
D-785
N/A
D-696
N/A
Flammability
Value
1.25–1.5g/cm3
<0.001% (hydrophobic)
20–30 Shore D
Decomposes at >400°C
5.5–6.5 × 10 –5 in/in –°F; 10 –4 °C –1
No outgassing except for entrained air
Non-flammable (UL rating V-O) Incompatible
with non-polar solvents and greases
208psi
891psi
35774psi
42.8%
91.3%
0.296
13.3% @ 250 lbs.
22.6% @ 500 lbs.
0.07
0.88
>1018W/cm
18V/µm
1.35
V-O
N/A
Yield Stress
Ultimate Stress
Young’s Modulus
Elongation in 2 in.
Elongation at Failure
Poisson’s Ratio
D-638
D-638
N/A
D-638
E-132
D-621
Deformation under Load
D-621
Absorbance (ax)
Emittance (e)
Volume Resistivity
Dielectric Strength
Refractive Index
Flammability Rating
N/A
N/A
N/A
D-149
D-542
UL-94
Photodiode Specifications
Silicon
190–1100nm
960nm
–20° to +60°C
–55° to +80°C
2.4mm × 2.4mm
—
—
—
—
Wavelength Range
Peak Sensitivity Wavelength
Operating Temperature
Storage Temperature
Active Area
Measurement Temperature
Thermistor Allowable Dissipation
Peltier Element
Allowable Current
Germanium
800–1800nm
1550nm
–55° to +60°C
–55° to +80°C
5.0mm (diameter)
—
—
—
—
Cooled Indium Gallium
Arsenide
900–1670nm
1550nm
–40° to +70°C
–55° to +85°C
3.0mm (diameter)
–10°C
0.2mW
1.5A
1.0A
OPTOELECTRONICS TEST
(Appropriate cables and connectors are required to operate the
Model 2500INT Integrating Sphere and must be ordered separately. They are not included with the instrument.)
7078-TRX-1
Low-Noise Triax Cable, 0.3m (1 ft)
7078-TRX-3
Low-Noise Triax Cable, 0.9m (3 ft)
7078-TRX-5
Low-Noise Triax Cable, 1.5m (5 ft)
7078-TRX-10
Low-Noise Triax Cable, 3.0m (10 ft)
7078-TRX-12
Low-Noise Triax Cable, 3.5m (12 ft)
7078-TRX-20
Low-Noise Triax Cable, 6.0m (20 ft)
2500INT-FC/APC FC/APC Connector for 2500INT
2500INT-FC/PC FC/PC Connector for 2500INT
2500INT-SMA SMA Connector for 2500INT
6172
2-Slot Male to 3-Lug Female Triax Adapter
0.987
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A
G R E A T E R
M E A S U R E
O F
C O N F I D E N C E
TEC SourceMeter Instrument
Autotuning TEC SourceMeter Instrument
The Models 2510 and 2510-AT TEC SourceMeter
instruments enhance Keithley’s CW (Continuous
Wave) test solution for high speed LIV (lightcurrent-voltage) testing of laser diode modules.
These 50W bipolar instruments were developed
in close cooperation with leading manufacturers
of laser diode modules for fiberoptic telecommunications networks. Designed to ensure tight
temperature control for the device under test,
the Model 2510 was the first in a line of highly
specialized instruments created for telecommunications laser diode testing. It brings together
Keithley’s expertise in high speed DC sourcing
and measurement with the ability to control the
operation of a laser diode module’s ThermoElectric Cooler or TEC (sometimes called a
Peltier device) accurately.
Ordering Information
2510
TEC SourceMeter
2510-AT Autotuning TEC
SourceMeter
Instrument
Accessories Supplied
User’s Manual, Input/Output
Connector
Accessories Available
2510-RH
2510-CAB
7007-1
7007-2
KPCI-488LPA
KUSB-488B
Resistive Heater Adapter for Model 2510
4-Wire Unshielded Cable, Phoenix Connector to
Unterminated End
Shielded IEEE-488 Cable, 1m (3.3 ft)
Shielded IEEE-488 Cable, 2m (6.6 ft)
IEEE-488 Interface/Controller for the PCI Bus
IEEE-488 USB-to-GPIB Adapter for USB Port
Services Available
2510-3Y-EW
1-year factory warranty extended to 3 years from
date of shipment
2510-AT-3Y-EW 1-year factory warranty extended to 3 years from
date of shipment
C/2510-3Y-DATA 3 (Z540-1 compliant) calibrations within 3 years
of purchase for Models 2510, 2510-AT*
*Not available in all countries
The Model 2510‑AT expands the capability of the
Model 2510 by offering autotuning capability. P,
I, and D (proportional, integral, and derivative) values for closed loop temperature control are determined by the instrument using a modified Zeigler-Nichols algorithm. This eliminates the need for
users to determine the optimal values for these coefficients experimentally. In all other respects, the
Model 2510 and Model 2510‑AT provide exactly the same set of features and capabilities.
The SourceMeter Concept
The Model 2510 and Model 2510-AT draw upon Keithley’s unique Source­Meter concept, which
combines precision voltage/current sourcing and measurement functions into a single instrument.
SourceMeter instruments provide numerous advantages over the use of separate instruments, including lower acquisition and maintenance costs, the need for less rack space, easier system integration
and programming, and a broad dynamic range.
Part of a Comprehensive LIV Test System
In a laser diode CW test stand, the Model 2510 or Model 2510-AT can control the temperature of
actively cooled optical components and assemblies (such as laser diode modules) to within ±0.005°C
of the user-defined setpoint. During testing, the instrument measures the internal temperature of
the laser diode module from any of a variety of temperature sensors, then drives power through
the TEC within the laser diode module in order to maintain its temperature at the desired setpoint.
Figure 1. The capabilities
of the Models 2510 and
2510-AT are intended to
complement those of other
Keithley instruments often
used in laser diode module
LIV testing, including the
Model 2400 and 2420
SourceMeter instruments,
the Model 2502 Dual Photo­
diode Meter, and the Model
2500INT Integrating Sphere.
Trigger Link
2510 or
2510-AT
Thermistor
Peltier
2400/
2420
2502
Fiber
Computer
GPIB
2500INT
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Precision temperature control for TECsSide
withText
autotuning PID for optimal performance
®
G R E A T E R
M E A S U R E
O F
OPTOELECTRONICS TEST
2510
2510-AT
C O N F I D E N C E
339
TEC SourceMeter Instrument
Autotuning TEC SourceMeter Instrument
• 50W TEC Controller combined
with DC measurement functions
• Fully digital P-I-D control
TMAX
Max.
Initial
Slope
• Autotuning capability for the
thermal control loop (2510-AT)
• Designed to control temperature
during laser diode module testing
• Wide temperature setpoint range
(–50°C to +225°C) and high
setpoint resolution (±0.001°C)
and stability (±0.005°C)
• Compatible with a variety of
temperature sensor inputs—
thermistors, RTDs, and IC sensors
• Measures and displays TEC
parameters during the control
cycle
L
Autotuning Function
The Model 2510‑AT Autotuning
TEC SourceMeter instrument
offers manu­facturers the ability
to automatically tune the temperature control loop required for CW testing of
optoelectronic components such as laser diode
modules and thermo-optic switches. This capability eliminates the need for time-consuming
experimentation to determine the optimal P-I-D
coefficient values.
TS
tL
Time
te
Figure 2.
Laser Diode TEC Minimum Overshoot
27
26
25
24
• 4-wire open/short lead detection
for thermal feedback element
23
• IEEE-488 and RS-232 interfaces
• Compact, half-rack design
63%
TSTART
• Maintains constant temperature,
current, voltage, and sensor
resistance
• AC Ohms measurement function
verifies integrity of TEC
Active temperature control is very
important due to the sensitivity
of laser diodes to temperature
changes. If the temperature varies, the laser diode’s dominant
output wavelength may change,
leading to signal overlap and
crosstalk problems.
Temp
Temp (°C)
Precision temperature control for TECsSide
withText
autotuning PID for optimal performance
2510
2510-AT
0
5
10
15
20
25
Time (s)
Figure 3.
Laser Diode TEC Minimum Settling Time
27
OPTOELECTRONICS TEST
Applications
Control and production testing
of thermoelectric coolers (Peltier
devices) in:
• Laser diode modules
• IR charge-coupled device (CCD)
arrays and charge-­injection
devices (CID)
• Cooled photodetectors
25
24
23
0
5
10
15
20
Time (s)
Figure 4.
25
The autotuning function offers users a choice of
a minimum settling time mode or a minimum
overshoot mode, which provides the Model
2510‑AT with the flexibility to be used with a
variety of load types and devices. For example,
when controlling a large area TEC in a test fixture optimized for P, I, and D values, minimum
overshoot protects the devices in the fixture
from damage (Figure 3). For temperature
setpoints that do not approach the maximum
specified temperature for the device under test,
the minimum settling time mode can be used to
speed up the autotuning function (Figure 4).
50W Output
As the complexity of today’s laser diode modules
increases, higher power levels are needed in
­temperature controllers to address the module’s
cooling needs during production test. The 50W
• Thermal-optic switches
• Temperature controlled fixtures
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Temp (°C)
26
The Model 2510‑AT’s P-I-D Auto-Tune software
employs a modified Ziegler-Nichols algorithm to
determine the coefficients used to control the
P-I-D loop. This algorithm ensures that the final
settling perturbations are damped by 25% each
cycle of the oscillation. The autotuning process
begins with applying a voltage step input to the
system being tuned (in open loop mode) and
measuring several parameters of the system’s
response to this voltage step function. The
system’s response to the step function is illustrated in Figure 2. The lag time of the system
response, the maximum initial slope, and the
TAU [63% (1/e)] response time are measured,
then used to generate the Kp (proportional gain
constant), Ki (integral gain constant), and Kd
(derivative gain constant) coefficients.
A
G R E A T E R
M E A S U R E
O F
C O N F I D E N C E
Open/Short Lead Detection
Both models of the instrument use a four-wire measurement method to
detect open/short leads on the temperature sensor before testing. Fourwire measure­ments eliminate lead resistance errors on the measured
value, reducing the possibility of false failures or device damage.
(5A @ 10V) output allows for higher testing speeds and a wider temperature setpoint range than other, lower-power ­solutions.
High Stability P-I-D Control
When compared with other TEC controllers, which use less sophisticated
P-I (proportional-integral) loops and hardware control mechanisms, this
instrument’s software-based, fully digital P-I-D control provides greater
temperature stability and can be easily upgraded with a simple firm­
ware change. The resulting temperature stability (±0.005°C short term,
±0.01°C long term) allows for very fine control over the output wavelength
and optical power of the laser diode module during production testing
of DC characteristics. This improved stability gives users higher confidence in measured values, especially for components or sub-assemblies
in wavelength multiplexed networks. The derivative component of the
instrument’s P-I-D control also reduces the required waiting time between
making measurements at various temperature setpoints. The temperature
setpoint range of –50°C to +225°C covers most of the test requirements for
production testing of cooled optical components and sub-assemblies, with
a resolution of ±0.001°C.
Interface Options
Like all newer Keithley instruments, both models of the instrument include
standard IEEE-488 and RS-232 interfaces to speed and simplify system integration and control.
Optional Resistive Heater Adapter
The Model 2510-RH Resistive
Heater Adapter enables either
model of the instrument to provide
closed loop temperature control
for resistive heater elements, rather
than for TECs. When the adapter is
installed at the instrument’s output
terminal, current flows through the
resistive heater when the P-I-D loop
indicates heating. However, no current will flow to the resistive heater
when the temperature loop calls
for cooling. The resistive element is
cooled through radiation, conducFigure 6. Optional heater adapter
tion, or convection.
Before the introduction of the Model 2510‑AT, configuring test systems for
new module designs and fixtures required the user to determine the best
combination of P, I, and D coefficients through trial-and-error experimentation. The Model 2510-AT’s autotuning function uses the modified ZeiglerNichols algorithm to determine the optimal P, I, and D ­values automatically.
Adaptable to Evolving DUT Requirements
The Model 2510 and Model 2510-AT are well suited for testing a wide range
of laser diode modules because they are compatible with the types of
temperature sensors most commonly used in these modules. In addition
to 100W, 1kW, 10kW, and 100kW thermistors, they can handle inputs
from 100W or 1kW RTDs, and a variety of solid-state temperature sensors.
This input flexibility ensures their adaptability as the modules being tested
evolve over time.
Comparison Data
0.01
2510 Measured
Competitor Measured
Programmable Setpoints and Limits
Users can assign temperature, current, voltage, and thermistor resistance
setpoints. The thermistor resistance setpoint feature allows higher correlation of test results with actual performance in the field for laser diode
modules because reference resistors are used to control the temperature
of the module. Programmable power, current, and temperature limits offer
maximum protection against damage to the device under test.
0.005
0
°C
-0.005
Accurate Real-Time Measurements
Both models can perform real-time measurements on the TEC, including
TEC current, voltage drop, power dissipation, and resistance, providing
valuable information on the operation of the thermal control system.
-0.01
Peltier (TEC) Ohms Measurement
TEC devices are easily affected by mechanical damage, such as sheer stress
during assembly. The most effective method to test a device for damage
after it has been incorporated into a laser diode module is to perform a
low-level AC (or reversing DC) ohms measurement. If there is a change in
the TEC’s resistance value when compared with the manufacturer’s specification, mechanical damage is indicated. Unlike a standard DC resistance
measurement, where the current passing through the device can produce
device heating and affect the measured resistance, the reversing DC ohms
method does not and allows more accurate measurements.
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Precision temperature control for TECsSide
withText
autotuning PID for optimal performance
TEC SourceMeter Instrument
Autotuning TEC SourceMeter Instrument
-0.015
One Hour Interval
Figure 5. This graph compares the Model 2510/2510-AT’s A/D converter resolution and temperature stability with that of a leading competitive instrument. While the competitive instrument uses an analog
proportional-integral (P-I) control loop, it displays information in
digital format through a low-resolution analog-to-digital converter. In
contrast, the Model 2510/2510-AT uses a high-precision digital P-I-D
control loop, which provides greater temperature stability, both over
the short term (±0.005°C) and the long term (±0.01°C).
A
G R E A T E R
M E A S U R E
O F
OPTOELECTRONICS TEST
2510
2510-AT
C O N F I D E N C E
341
2510
2510-AT
TEC SourceMeter Instrument
Autotuning TEC SourceMeter Instrument
SPECIFICATIONS
TEC Output SPECIFICATIONS
OUTPUT RANGE: ±10VDC at up to ±5ADC.15
OUTPUT RIPPLE: <5mV rms9.
AC RESISTANCE EXCITATION: ±(9.6mA ± 90µA).14
The Models 2510 and 2510-AT TEC SourceMeter instruments are designed to:
• Control the power to the TEC to maintain a constant temperature, current, voltage, or thermistor resistance.
• Measure the resistance of the TEC.
• Provide greater control and flexibility through a software P-I-D loop.
TEC MEASUREMENT SPECIFICATIONS3
Function
Operating Resistance 2, 10, 11, 12
Operating Voltage 2,10
Operating Current10
AC Resistance 2, 18
Model 2510, 2510-AT
Side Textspecifications
CONTROL SYSTEM SPECIFICATIONS
SET: Constant Peltier Temperature, Constant Peltier Voltage, Constant Peltier Current. Constant
Thermistor Resistance.
CONTROL METHOD: Programmable software PID loop. Proportional, Integral, and Derivative
gains independently program­mable.
SETPOINT SHORT TERM STABILITY: ±0.005°C rms1,6,7.
SETPOINT LONG TERM STABILITY: ±0.01°C1,6,8.
SETPOINT RANGE: –50°C to 225°C.
UPPER TEMPERATURE LIMIT: 250°C max.
LOWER TEMPERATURE LIMIT: –50°C max.
SETPOINT RESOLUTION: ±0.001°C, <±400µV, <±200µA 0.01% of nominal (25°C) thermistor
resistance.
Hardware Current Limit: 1.0A to 5.25A ±5%.
Software Voltage Limit:±0.5 to 10.5V ±5%.
Sensor Type
RTD
Nominal Resistance Range
Excitation Accuracy1,3
Nominal Sensor
Temperature Range
Calibration
Measurement Accuracy1,3
±(% rdg + offset)
100 W
2.5 mA
4 V max
0–250 W
±1.5%
Thermistor
Nominal
Thermistor
Resistance
100
W
1kW
10kW
100kW
Solid State
Current
Voltage
Output (Iss)
Output (Vss)
+13.5 V
2.5 mA
833 µA
15.75V max
0–2.50 kW
±2.9%
100 W
2.5 mA
8 V max
0–1 kW
±2.9%
1 kW
833 µA
8 V max
0–10 kW
±2.9%
10 kW
100 µA
8 V max
0–80 kW
±2.9%
100 kW
33 µA
6.6 V max
0–200 kW
±2.9%
–50° to +250°C
–50° to +250°C
–50° to +250°C
–50° to +250°C
–50° to +250°C
–50° to +250°C
α, β, δ settable
α, β, δ settable
A, B, C settable
A, B, C settable
A, B, C settable
A, B, C settable
Slope & offset
±2.9%
–40° to +100°C
Slope & offset
0.04 + 0.07 W2
0.04 + 0.04 W2
0.04 + 0.07 W2
0.04 + 0.4 W2
0.02 + 3 W
0.04 + 21 W
0.03 + 100 nA
0.03 + 500 µV
1 kW
833 µA
General
Thermistor Measurement Accuracy19
OPTOELECTRONICS TEST
OPEN SHORTED THERMOELECTRIC DETECTION
LOAD IMPEDANCE: Stable into 1µF typical.
COMMON MODE VOLTAGE: 30VDC maximum.
COMMON MODE ISOLATION: >109W, <1500pF.
MAX. VOLTAGE DROP BETWEEN INPUT/OUTPUT SENSE TERMINALS: 1V.
MAX. SENSE LEAD RESISTANCE: 1W for rated accuracy.
MAX. Force LEAD RESISTANCE: 0.1W.
SENSE INPUT IMPEDANCE: >400kW.
thermal feedback element SPECIFICATIONS3
Excitation13
Accuracy vs. Temperature
0°C
25°C
50°C
100°C
0.021°C 0.035°C 0.070°C
0.27°C
0.015°C 0.023°C 0.045°C
0.18°C
0.006°C 0.012°C 0.026°C
0.15°C
0.009°C 0.014°C 0.026°C
0.13°C
OPEN/SHORTED ELEMENT DETECTION
SOFTWARE LINEARIZATION FOR THERMISTOR
AND RTD
Common Mode Voltage: 30VDC.
Common Mode Isolation: >109W, <1000pF.
Max. Voltage Drop Between Input/Output Sense
­Terminals: 1V.
Max. Sense Lead Resistance: 100W for rated accuracy.
Sense Input Impedance: >108W.
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1 Year, 23°C ±5°C
±(2.0% of rdg + 0.1W)
±(0.1% of rdg + 4mV)
±(0.4% of rdg + 8mA)
±(0.10% of rdg + 0.02W)
NOTES
NOISE REJECTION:
SPEED NPLCNMRR CMRR
16
Normal
1.00
60 dB
17
120 dB1
SOURCE OUTPUT MODES: Fixed DC level.
PROGRAMMABILITY: IEEE-488 (SCPI-1995.0), RS-232,
3 user-­definable power-up states plus factory default
and *RST.
POWER SUPPLY: 90V to 260V rms, 50–60Hz, 75W.
EMC: Complies with European Union Directive 98/336/EEC
(CE marking require­ments), FCC part 15 class B, CTSPR
11, IEC 801-2, IEC 801-3, IEC 801-4.
VIBRATION: MIL-PRF-28800F Class 3 Random Vibration.
WARM-UP: 1 hour to rated accuracies.
DIMENSIONS, WEIGHT: 89mm high × 213 mm high ×
370mm deep (3½ in × 83 ⁄8 in × 149 ⁄16 in). Bench configuration (with handle and feet): 104mm high × 238mm
wide × 370mm deep (41 ⁄8 in × 93 ⁄8 in × 149 ⁄16 in). Net
Weight: 3.21kg (7.08 lbs).
ENVIRONMENT: Operating: 0°–50°C, 70% R.H. up to
35°C. Derate 3% R.H./°C, 35°–50°C. Storage: –25°
to 65°C.
A
±12%
–40° to +100°C
G R E A T E R
1. Model 2510 and device under test in a regulated ambient temperature
of 25°C.
2. With remote voltage sense.
3. 1 year, 23°C ±5°C.
4. With ILoad = 5A and V Load = 0V.
5. With ILoad = 5A and V Load = 10V.
6. With 10kW thermistor as sensor.
7. Short term stability is defined as 24 hours with Peltier and Model 2510
at 25°C ±0.5°C.
8. Long term stability is defined as 30 days with Peltier and Model 2510 at
25°C ±0.5°C.
9. 10Hz to 10MHz measured at 5A output into a 2W load.
10.Common mode voltage = 0V (meter connect enabled, connects Peltier
low output to thermistor measure circuit ground). ±(0.1% of rdg. +
0.1W) with meter connect disabled.
11. Resistance range 0W to 20W for rated accuracy.
12.Current through Peltier > 0.2A.
13.Default values shown, selectable values of 3µA, 10µA, 33µA, 100µA,
833µA, 2.5mA. Note that temperature control performance will
degrade at lower c­ urrents.
14. AC ohms is a dual pulsed meas­urement using current reversals available over bus only.
15. Settable to <400µV and <200µA in constant V and constant I mode
respectively.
16.For line frequency ±0.1%.
17. For 1kW unbalance in LO lead.
18.Resistance range 0W to 100W for rated accuracy.
19. Accuracy figures represent the uncertainty that the Model 2510 may add
to the temperature measurement, not including thermistor uncertainty.
These accuracy figures are for thermistors with typical A,B,C constants.
M E A S U R E
O F
C O N F I D E N C E
• Compatible with Keithley laser
diode LIV test solutions
• Simplifies configuration of LIV
test systems
• Choice of three fixture designs,
all with necessary cables
• Cables also available separately
• Ambient temperature control on
TEC version
Ordering Information
8542
Dual In-Line (DIL)
Telecom Laser Diode
Mount Bundle
with 8542-301 and
CA-321-1 cables
8544
Butterfly Telecom
Laser Diode Mount
Bundle with 8542-301
and CA-321-1 cables
8544-TEC Butterfly Telecom
Laser Diode Mount
Bundle with TEC,
thermistor, and
AD592CN temperature
sensor, with 8542-301
and CA-322-1 cables
Lasers not included
Three different fixture bundle designs are available, all of which are compatible with Keithley’s popular laser diode LIV test systems. Each bundle includes all cabling required to connect the test instrumentation to the test fixture. Cables are also available separately.
All 14 pin DIL and butterfly laser packages can
be mounted on the 854X Series. For higher
power butterfly packages without integral thermoelectric coolers (TECs), the Model 8544-TEC
offers a TEC and both thermistor and AD592CN
sensors.
APPLICATIONS
• Continuous wave laser diode
LIV characterization
SPECIFICATIONS
This series covers the offering of Laser Diode Mounts (LDM) for
use with Continuous LIV Test Solutions. The following products:
2400-LV/2420/2440, 2500/2502, and 2510/2510AT are recommended for use with these products.
General
Recommended Maximum Ratings5:
Drive Current (Amps): 2.
Measured Voltage (Volts): 3.
Weight6: 1.0 lbs (0.45kg).
Dimensions6: 32mm high × 95mm wide × 140mm deep
(1.2in × 3.75 in × 5.5 in).
Laser Temperature Control
Accessories Supplied
8542-301 LIV Cable to connect
Model 2500 and 24XX
to the fixture, 1.8m (6
ft.) (supplied with 8542,
8544, and 8544-TEC)
CA-321-1 Temp Control Cable
to connect Model
2510 to fixture, 1.8m
(6 ft.) (supplied with
8542 and 8544)
CA-322-1 Dual Temp Control
Cable to ­connect (2)
Model 2510 to fixture,
1.8m (6 ft.) (supplied
with 8544-TEC)
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The 854X Laser Diode Mount
Series makes it easier than ever
to configure a complete laser
diode LIV test system for continuous wave test applications.
These fixtures provide highly
stable temperature control for
all telecommunications laser
diodes. They offer an easy-to-use
platform for testing laser diodes
used in telecommunications.
They are designed to speed and
simplify setting up test systems
for all laser diode/photodiode/
thermoelectric cooler/thermistor
configurations.
Laser diode fixtures
Side for
TextLIV test systems
Laser Diode Mounts for LIV Test Systems
Temperature Range: 0° to +80°C.
Sensor Type 2 (Model 8544-TEC Only): 10kW thermistor,
AD592CN.
Referenced Mount Specifications
Laser Diode Package
Model
Socket
8542
DIL 14 pin
Base
Plate
Position
adjustable
8544
8544-TEC
Butterfly 14 pin Butterfly 14 pin
0.1˝ centers
0.1˝ centers
Accessories Available
2400-LV/2420/2440SourceMeter® Instruments1
2502
Dual Photodiode Meter
2510/2510AT
TEC Control Meters (AT: Auto Tune feature)
A
G R E A T E R
Notes
1. The other SourceMeter offerings from Keithley, Models 2400, 2410,
2425, and 2430, are not recommended for use with the 8542-301 and
Laser Diode Mounts unless proper interlock and safety precautions are
observed (especially voltage protection).
2. The 8544-TEC unit is shipped with the 10kW thermistor wired. This is
the more commonly requested configuration. The AD592CN sensor
wires are available but not connected.
3. The triax inner shield is available on pin 2 of the 8542-301A. This will
allow flexibility for the customer to exchange the wire in the LDM
from pin 6 to pin 2.
4. To use the second 2510 (DB-15 pins 9–15), the customer must internally
wire the 8544-TEC Mount to the DUT thermocouple. See the Quick
Start Guide for wiring configuration.
5. Ratings are based on use of mount with provided cables and average
majority of laser diode ­characteristics.
6. The weight and dimension is the mounting unit without the cables.
M E A S U R E
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OPTOELECTRONICS TEST
8542, 8544,
8544-TEC
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7090
Optical Switch Cards
The Model 7090 Optical Switch Cards are
members of Keithley’s family of switch cards
designed for the Models 7001 and 7002 Switch
Main­frames. These cards simplify making
accurate connections from one input fiber
channel to either eight or sixteen output fiber
channels. When combined with existing Series
7001/7002 switch cards, these optical switches
allow for hybrid switching combinations of optical, RF, and DC switching within a single switch
mainframe, extending the automated testing
­environment.
Optical switching card for the
Side
Model
Text 7001 switching mainframe
Use with 7001 and 7002
scanner mainframes.
Combine Optical, DC, and RF
Switching in One Instrument
The Model 7090 cards are compatible with all
other Series 7001/7002 switch cards, so they can
be used in conjunction with DC switch cards
to control an LIV test system, as well as for RF
switching needs. All of the switches can be used
in one mainframe with a single GPIB address.
• Perform multiple tests on a
single device without changing
test setup
• Test multiple devices with a
single instrument
• 1×8 and 1×16 optical switching
cards
• Single-mode or multimode fiber
• Very low insertion loss,
0.6dB typ.
• 0.03dB repeatability
• FC/SPC connectors
OPTOELECTRONICS TEST
• Bulkhead options available
Seamless Integration with Keithley’s LIV Test Solution
The Model 7090 cards are designed to allow tight integration with Keithley’s LIV Test System. The LIV
Test System combines all of the DC measurement capabilities required to test laser diode modules,
including optical power measurement and tight temperature control of the device under test, in an
integrated instrument package. The high speed Trigger Link interface provided on the instruments
and switch mainframe in the LIV Test System allows for tight synchronization of system functions.
Faster Test Development
Several built-in features of the Models 7001
and 7002 mainframes simplify system setup,
operation, and modifications. All aspects of the
instrument can be programmed from either the
mainframe’s front panel or over the IEEE bus.
Both mainframes offer Trigger Link interfaces
to ensure tight control over the test system and
eliminate IEEE bus command overhead.
Applications
Production testing of:
• Laser diode modules
• Chip on submount laser diodes
• Laser diode bars
• LEDs and OLEDs
• Passive optical components
• VCSEL arrays
• Optical add/drop multiplexer
(OADM)
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Meets a Range of
Test Requirements
Model 7090 cards offer a number of options
to ensure the compatibility of the switch with
the test setup. Each switch card has one input fiber aligned to one of eight or sixteen output fibers.
Depending on the card chosen, the fiber is either a 9µm ­single-mode fiber or 62.5µm multimode
fiber. The input and output fiber channels are available with several connection options, including
FC/SPC and a one-meter fiber pigtail with a connector. For a complete list of available features, see
the Physical Properties table on the following page.
A
G R E A T E R
M E A S U R E
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C O N F I D E N C E
Ordering Information
7090-8-41×8 Multimode with
FC/SPC Fiber Pigtail
7090-16-61×16 Single-Mode with
FC/SPC Fiber Pigtail
Accessories Supplied
User’s Manual
Optical Switch Cards
Physical Properties
Configuration: Single channel, 1×N non-blocking switch.
Model No. of
Number
Channels
Fiber Type
7090-8-4
1×8
Multimode fiber 62.5/125 each ch.
7090-16-6
1×16
Single-mode fiber (SMF-28)
9/125 each ch.
7011-C Quad 1×10 Multiplexer Card
7012-C4×10 Matrix Card
7053 High Current Switch Card
7016A 2GHz, Dual 1×4, 50W Card
7017 800MHz Card
7038 2GHz, 75W Card
1290-1650
FC/SPC
Fiber
Length
1m
1m
Referenced Switch Manufacturer’s Optical Specifications 1
Wavelength Range
Switch Life Insertion Loss 2
Repeatability 3
Back Reflection (SM/MM) 4
Polarization Dependent Loss (PDL) 5
Crosstalk
Related DC/RF
Switch Options
Wavelength
(nm)
Connector
780-1350
FC/SPC
Typical
MaximumUnits
780 to 1650
nm
> 10 million cycles (min.)
0.6
1.2dB
—
±0.03dB
–60 / –20
–55 / —
dB
—
0.05dB
—
–80
dB
General
Switching Time6:1×81×16
Reset/Open 315ms450ms
Settle/Close 500ms630ms
Dimensions, Weight: 144mm wide × 272mm high × 32mm deep (4.5 in × 10.75 in × 1.25 in). Net weight 0.66kg (1.5 lb).
Environment: Operating Temperature: 0° to 40°C7. Storage Temperature: –20° to 65°C. Relative Humidity: Up to 35°C
<80% RH non-condensing.
EMC: European Union Directive 89/336/EEC EN61326.
Safety: European Union Directive 73/23/EEC EN61010-1.
Model 7090
Sidespecifications
Text
7090
Services Available
Notes
1. All optical specifications are referenced without connectors and are guaranteed by switch manufacturer only. Connectorization data will be provided
for Insertion Loss and Back Reflection for each channel per switch card.
2. Measured at 23° ± 5°C.
3. Sequential repeatability for 100 cycles at constant temperature after warm up. (Difference in Insertion Loss).
4. Based on standard 1m pigtail length.
5. Measured at 1550nm.
6. Actuation time measured from system trigger. Reset/Open refers to Channel N to Reset time. Settle/Close refers to Reset to Channel N or Channel N to
Channel M time. Reset position is optically blocked.
7. At higher operating temperatures, a typical additive insertion loss of 0.1dB should be expected for the strain relief model (0.3dB for the bulkhead model).
OPTOELECTRONICS TEST
7090-16-6-3Y-EW 1-year factory warranty extended to 3 years
from date of shipment
7090-8-4-3Y-EW 1-year factory warranty extended to 3 years
from date of shipment 1.888.KEITHLEY (U.S. only)
w w w.keithley.com
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OPTOELECTRONICS TEST
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C O N F I D E N C E
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