Manual-3540A 3541ABC 10340A 10341ABC

Manual-3540A 3541ABC 10340A 10341ABC
2015 W. Chestnut Street Alhambra, CA 91803-1542 Tel: 626-293-3400 • Fax: 626-293-3428
Operator's Manual
Fiberoptic Transmitter
Models 3540A, 3541A/B/C,
3740A, 3741A, 10340A,
10341A/B/C, 10370A,
10371A
MAN-3540A Rev B
Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Disclaimer
Every attempt has been made to make this material complete, accurate, and up-to-date.
Users are cautioned, however, that Ortel, a Division of Emcore, reserves the right to make
changes without notice and shall not be responsible for any damages, including
consequential, caused by reliance on the material presented, including, but not limited to,
typographical, arithmetical, or listing errors.
Copyright Information
© 2004 by Ortel, a Division of Emcore
Ortel, a Division of Emcore
Alhambra, California, 91803, USA
July 27, 2004
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Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
WARNINGS, CAUTIONS, AND GENERAL NOTES
Safety Considerations
When installing or using this product, observe all safety precautions during handling and
operation. Failure to comply with the following general safety precautions and with specific
precautions described elsewhere in this manual violates the safety standards of the
design, manufacture, and intended use of this product. Ortel assumes no liability for the
customer's failure to comply with these precautions.
Calls attention to a procedure or practice, which, if ignored, may result in damage
to the system or system component. Do not perform any procedure preceded by a
CAUTION until described conditions are fully understood and met.
Electrostatic Sensitivity
ESD = Electrostatic Sensitive Device
Observe electrostatic precautionary procedures.
Semiconductor laser transmitters and receivers provide highly reliable performance when
operated in conformity with their intended design. However, a semiconductor laser may
be damaged by an electrostatic charge inadvertently imposed by careless handling.
Static electricity can be conducted to the laser chip from the center pin of the RF input
connector, and through the DC connector pins. When unpacking and otherwise handling
the transmitter, follow ESD precautionary procedures including use of grounded wrist
straps, grounded workbench surfaces, and grounded floor mats.
Exposure to electrostatic charge is greatly reduced after the transmitter has been installed
in an operational circuit.
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Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
If You Need Help
If you need additional help in installing or using the system, need additional copies of this
manual, or have questions about system options, please call Ortel's Sales Department.
Service
Do not attempt to modify or service any part of the system other than in accordance with
procedures outlined in this Operator's Manual. If the system does not meet its warranted
specifications, or if a problem is encountered that requires service, return the apparently
faulty plug-in or assembly to Ortel for evaluation in accordance with Ortel's warranty policy.
When returning a plug-in or assembly for service, include the following information:
Owner, Model Number, Serial Number, Return Authorization Number (obtained in advance
from Ortel’s Customer Service Department), service required and/or a description of the
problem encountered.
Warranty and Repair Policy
The Ortel Quality Plan includes product test and inspection operations to verify the quality
and reliability of our products.
Ortel uses every reasonable precaution to ensure that every device meets published
electrical, optical, and mechanical specifications prior to shipment. Customers are asked
to advise their incoming inspection, assembly, and test personnel as to the precautions
required in handling and testing ESD sensitive opto-electronic components.
These products are covered by the following warranties:
1.
General Warranty
Ortel warrants to the original purchaser all standard products sold by Ortel to be
free of defects in material and workmanship for one (1) year from date of shipment
from Ortel. During the warranty period, Ortel's obligation, at our option, is limited to
repair or replacement of any product that Ortel proves to be defective. This
warranty does not apply to any product, which has been subject to alteration,
abuse, improper installation or application, accident, electrical or environmental
over-stress, negligence in use, storage, transportation or handling.
2.
Specific Product Warranty Instructions
All Ortel products are manufactured to high quality standards and are warranted
against defects in workmanship, materials and construction, and to no further
extent. Any claim for repair or replacement of a device found to be defective on
incoming inspection by a customer must be made within 30 days of receipt of the
shipment, or within 30 days of discovery of a defect within the warranty period.
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Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
This warranty is the only warranty made by Ortel and is in lieu of all other
warranties, expressed or implied, except as to title, and can be amended only by a
written instrument signed by an officer of Ortel. Ortel’s sales agents or
representatives are not authorized to make commitments on warranty returns.
In the even that it is necessary to return any product against the above warranty,
the following procedure shall be followed:
a.
Return authorization shall be received from the Ortel’s Sales Department
prior to returning any device. Advise the Ortel Sales Department of the
model, serial number, and the discrepancy. The device shall then be
forwarded to Ortel, transportation prepaid. Devices returned freight collect
or without authorization may not be accepted.
b.
Prior to repair, Ortel Sales will advise the customer of Ortel’s test results
and will advise the customer of any charges for repair (usually for customer
caused problems or out-of-warranty conditions).
If returned devices meet full specifications and do not require repair, or if
the customer does not authorize non-warranty repairs, the device may be
subject to a standard evaluation charge. Customer approval for the repair
and any associated costs will be the authority to begin the repair at Ortel.
Customer approval is also necessary for any removal of certain parts, such
as connectors, which may be necessary for Ortel testing or repair.
c.
3.
Repaired products are warranted for the balance of the original warranty
period, or at least 90 days from date of shipment.
Limitations of Liabilities
Ortel's liability on any claim of any kind, including negligence, for any loss or
damage arising from, connected with, or resulting from the purchase order,
contract, or quotation, or from the performance or breach thereof, or from the
design, manufacture, sale, delivery, installation, inspection, operation or use of any
equipment covered by or furnished under this contract, shall in no case exceed the
purchase price of the device which gives rise to the claim.
EXCEPT AS EXPRESSLY PROVIDED HEREIN, ORTEL MAKES NO
WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED, WITH RESPECT TO
ANY GOODS, PARTS AND SERVICES PROVIDED IN CONNECTION WITH
THIS AGREEMENT INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE. ORTEL SHALL NOT BE LIABLE FOR ANY OTHER DAMAGE
INCLUDING, BUT NOT LIMITED TO, INDIRECT, SPECIAL OR
CONSEQUENTIAL DAMAGES ARISING OUT OF OR IN CONNECTION WITH
FURNISHING OF GOODS, PARTS AND SERVICE HEREUNDER, OR THE
PERFORMANCE, USE OF, OR INABILITY TO USE THE GOODS, PARTS AND
SERVICE.
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Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Ortel will not be responsible for loss of output or reduced output of opto-electronic
devices if the customer performs chip mounting, ribbon bonding, wire bonding,
fiber coupling, fiber connectorization, or similar operations. These processes are
critical and may damage the device or may affect the device's output or the fiber
output.
Ortel test reports or data indicating mean-time-to-failure, mean-time-betweenfailure, or other reliability data are design guides and are not intended to imply that
individual products or samples of products will achieve the same results. These
numbers are to be used as management and engineering tools, and are not
necessarily indicative of expected field operation. These numbers assume a
mature design, good parts, and no degradation of reliability due to manufacturing
procedures and processes.
Ortel is not liable for normal laser output degradation or fiber coupling efficiency
degradation over the life of the device.
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Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
DANGER
This fiberoptic laser transmitter contains a class IIIb laser product as defined by the U.S.
Department of Health and Human Services, Public Health Service, Food and Drug Administration.
This laser product complies with 21 CFR, Chapter I, Subchapter J of the DHEW standards under
the Radiation Control for Health and Safety Act of 1968. The laser module certification label is
located on the top of the transmitter enclosure and it also shows the required DANGER warning
logotype (as shown below).
The Ortel laser products are used in optical fiber communications systems for radio frequency and
microwave frequency analog fiberoptic links. In normal operation, these systems are fully
enclosed and fully shielded by the hermetically sealed laser metal package. Laser bias current is
limited by the internal control circuitry. The transmitters are coupled to glass fiber and have 1300
nm optical output wavelength with typically .5 to 7 mW output depending on the model. The
optical radiation is confined to the fiber core. Under these conditions, there is no accessible laser
emission and hence no hazard to safety or health. Variations in the different models reflect the
bandwidth, optical output, noise, and distortion of the laser.
Since there is no human access to the laser output during system operation, no special operator
precautions are necessary when fiber is connected to the transmitter and receiver. During
installation, service, or maintenance, the service technician is warned, however, to take
precautions, which include not looking directly into the fiber connector or the fiber, which
is connected to the fiber connector before it is connected to the fiberoptic receiver. The
light emitted from the fiberoptic connector or any fiber connected to the connector is
invisible and may be harmful to the human eye. Use either an infrared viewer or
fluorescent screen for optical output verification. All handling precautions as outlined by
the FDA and ANSI Z136.2 and other authorities of class IIIb lasers must be observed.
Do not attempt to modify or to service the laser transmitter. Return it to Ortel for service and
repair. Contact the Ortel’s Customer Service Department for a return authorization if service is
necessary.
DANGER
INVISIBLE LASER RADIATION
AVOID DIRECT EXPOSURE TO BEAM
PEAK POWER 30 mW
WAVELENGTH 1300/1550 nm
CLASS IIIb LASER PRODUCT
THIS PRODUCT COMPLIES WITH 21 CFR
CHAPTER I SUBCHAPTER J
AVOID EXPOSUREINVISIBLE LASER
RADIATION IS EMITTED
FROM THIS APERTURE
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Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Table of Contents
1.0
General Information............................................................................................................................................ 9
1.1
Description ........................................................................................................................................... 9
1.2
Specifications..................................................................................................................................... 10
1.3
Identification and Model Numbers................................................................................................... 10
1.3.1
Options................................................................................................................................. 10
1.4
Instructions for Service Returns...................................................................................................... 11
1.5
Additional Manuals............................................................................................................................ 11
2.0
Safety Precautions............................................................................................................................................
2.1
Safety Symbols...................................................................................................................................
2.2
ESD Sensitive.....................................................................................................................................
2.3
RF Connector .....................................................................................................................................
2.4
Power Supply .....................................................................................................................................
2.5
Grounding...........................................................................................................................................
2.6
Input RF Power...................................................................................................................................
2.7
Storage................................................................................................................................................
2.8
Do Not Attempt to Modify or Service ...............................................................................................
12
12
12
13
13
13
13
13
13
3.0
Theory of Operation..........................................................................................................................................
3.1
Semiconductor Laser ........................................................................................................................
3.2
Optical Systems ................................................................................................................................
3.3
Temperature Control .........................................................................................................................
3.4
Power Control ....................................................................................................................................
3.5
External Displays and Controls........................................................................................................
3.5.1
LED Displays .......................................................................................................................
3.5.2
Status Monitors....................................................................................................................
3.5.3
Alarm Functions...................................................................................................................
14
14
14
15
15
15
15
16
16
4.0
Installation .......................................................................................................................................................... 18
4.1
Unpacking and Visual Inspection ..................................................................................................... 18
4.2
Operating Conditions ......................................................................................................................... 18
4.3
Electrical Connection ......................................................................................................................... 19
4.3.1
DC Connection ..................................................................................................................... 19
4.3.1.1 User Supplied Power Supplies ............................................................................... 19
4.3.1.2 Model 10990A & 10901AB Power Supplies ........................................................... 20
4.3.2
Optical Connection.............................................................................................................. 22
4.3.3
RF Connection ..................................................................................................................... 22
4.3.4
Optical Power ....................................................................................................................... 23
4.3.5
General Considerations ...................................................................................................... 23
4.4
Initial Turn On Procedure .................................................................................................................. 24
4.4.1
DC Operation........................................................................................................................ 24
4.4.2
RF Operation ........................................................................................................................ 25
4.5
Performance Verification Procedure ................................................................................................ 26
4.5.1
Frequency Response........................................................................................................... 26
4.5.2
VSWR .................................................................................................................................... 26
4.5.3
Noise Measurements........................................................................................................... 26
Figure 4.1: Frequency Response, VSWR ......................................................................................................................
Figure 4.2: EIN; RIN..........................................................................................................................................................
Product Specification Table ............................................................................................................................................
Outline Drawing, Dimensions, and Pinouts...................................................................................................................
8
29
29
30
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Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Chapter 1
1.0
General Information
1.1
Description
This manual covers the operation of the following high-speed laser transmitter
models:
MODEL #
Maximum
Frequency
Wavelength
Flange-mount
Plug-in
(for 19" rack)
3540A
10340A
5 GHz
1310 nm
3541A
10341A
10 GHz
1310 nm
3541B
10341B
13 GHz
1310 nm
3541C
10341C
15 GHz
1310 nm
3740A
10370A
4 GHz
1550 nm
3741A
10371A
10 GHz
1550 nm
These transmitters feature singlemode fiber, an optical isolator, a high speed
laser, circuits for the transmission of analog modulated optical signals with
superior signal quality, and a package designed for compatibility with microwave
and RF analog and telemetry signals.
CAUTION:
Carefully read all of Section 4 of this manual before attempting to
operate the laser transmitter.
Each transmitter has an InGaAsP semiconductor, Distributed Feedback (DFB)
laser with 1300 nm singlemode fiber coupled to its output, and a wideband
microwave input circuit internally matched to 50 Ω. The laser chip is cathode
grounded, and the input circuit is available either AC or DC coupled.
Each transmitter contains electronic circuits to stabilize the laser temperature
and optical output power over a wide environmental range. Also, status
monitoring and alarm circuits are included for use in systems that require selfdiagnosis and failure analysis.
Each transmitter has a standard SMA jack connector for RF input.
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Ortel, a Division of Emcore
Fiberoptic Transmitters
1.2
Man-3540A Rev B
Specifications
For detailed specifications of the product described in this manual, consult the
individual Product Specification Table (PST) in Appendix A at the end of this
manual.
Specifications apply over the entire specified operating range of the product and
are guaranteed for 1 year after the date of shipment.
1.3
Identification and Model Numbers
Each laser is assigned a unique model number and serial number that appears on
the label. Model numbers for this series have the form such as 3541A.
1.3.1 Options
These lasers have the following standard performance options, which are
designated by numeric suffixes to the model number, separated by a
hyphen. Thus, 3541A-001 describes a laser with the input AC coupling
capacitor deleted (Option 001). The performance of a product with any
standard option is described on the Product Specification Table.
There is one standard electrical option available.
Option -001: DC coupled electrical input
This option removes the input series capacitor in the laser transmitter.
Thus, the transmitter can be modulated at frequencies <100 kHz. This
option is for the convenience of the user only. The RF parameters are not
measured or guaranteed below 0.01 GHz. For this DC coupled option the
center pin of the laser input will be at a positive voltage, therefore a DC
blocking capacitor must be used in the input RF circuit, as outlined in
section 4.3.3
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Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
The standard optical connector options follow:
Option #
Connector
Style
Cable
Available in
Flange-mount
Available in
Plug-in
-020
FC/APC
bulkhead
x
x
-021
FC/SPC
bulkhead
x
x
-022
FC/APC
3 mm diam.
x
-023
FC/SPC
3 mm diam.
x
-026
FC/PC
bulkhead
x
-028
FC/PC
3 mm diam.
x
x
Products with modified performance can be bought in accordance with
individual customer requirements.
They are designated by an
alpha-numeric suffix,
-ANN
where A is alpha, and N is numeric. Such custom options should be
discussed in advance with your Ortel sales representative for detailed
performance and pricing.
1.4
Instructions for Service Returns
If the laser transmitter does not meet its warranted specifications, it must be
returned to Ortel for test and evaluation, in accordance with Ortel's warranty policy.
When returning the transmitter for service or repair, include the following
information: owner, model number, serial number, return authorization number
(obtained from Ortel’s Customer Service), service required and/or a description of
the problem encountered.
For safe shipment of the transmitter, use anti-static materials. The original packing
material is reusable.
1.5
Additional Manuals
Additional copies of this manual are available through the Ortel’s Sales
Department. Specify the Model Number from the title page or from your laser
transmitter.
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Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Chapter 2
2.0
Safety Precautions
Semiconductor lasers are high performance electronic devices that provide highly reliable
performance when operated in conformance with their intended design.
For best results when using this product, general safety precautions must be observed
during handling and operation.
Failure to comply with the general safety and with the specific precautions described in this
manual would violate the safety standards of the design, manufacture, and intended use
of the device. Ortel assumes no liability for the customer's failure to comply with these
precautions.
2.1
Safety Symbols
ESD Sensitive Device:Observe electrostatic precautionary procedures.
2.2
DANGER:
Indicates a hazard. It is to call attention to a procedure or practice
which, if ignored, could lead to personal injury. Do not continue
beyond the DANGER sign until the described conditions are fully
understood and met.
CAUTION:
Indicates a hazard. It is to call attention to a procedure or practice
which, if ignored, could lead to damage to the laser transmitter or
other equipment. Do not continue beyond the CAUTION sign until
the described conditions are fully understood and met.
ESD Sensitive
Semiconductor lasers are static sensitive devices, and products containing them
should be treated accordingly. Static electricity can be conducted to the laser chip
from the center pin of the RF input SMA connector, and through the DC connector
pins. When unpacking and handling the laser transmitter prior to installing it, use
ESD precautionary procedures, such as grounded wrist straps and grounded work
mats.
After the laser is installed in an operational circuit, these pins are protected from
unintentional contact and ESD sensitivity is greatly reduced.
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Ortel, a Division of Emcore
Fiberoptic Transmitters
2.3
Man-3540A Rev B
RF Connector
Do not apply excessive torque to the SMA connector. The use of standard
wrenches can lead to a damaged connector. Use 7-9 inch pounds of torque. The
use of a torque wrench is strongly recommended.
2.4
Power Supply
Operating the transmitter outside of its maximum ratings may cause device failure
or a safety hazard. See section 4.3.1 for more details.
2.5
Grounding
All power supplies should be connected to an earth ground.
2.6
Input RF Power
The laser can be overdriven and damaged by the application of excessive RF input
power. Refer to the Product Specification Table for information about the
maximum input power.
2.7
Storage
Observe ESD precautions while storing the laser transmitter (i.e. anti-static
containers) and store away from corrosive materials. Storage temperature: -40ºC
to +85ºC.
2.8
Do Not Attempt to Modify or Service
Do not attempt to modify or service any part of the device. Doing so will void the
warranty. Return it to Ortel for service and repair. Contact the Ortel’s Customer
Service Department for a return authorization number.
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Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Chapter 3
3.0
Theory of Operation
3.1
Semiconductor LaserError! Bookmark not defined.
The semiconductor laser type contained in these transmitters is a Distributed
Feedback (DFB) type, Indium Gallium Arsenide Phosphide (InGaAsP), buried
heterostructure laser. DFB lasers incorporate a grating structure along the length
of the active area, which provides positive feedback only at the optical frequency of
interest. Thus a DFB laser only emits light at one wavelength. Since the optical
spectrum of the laser shows only one peak, the laser may operate in highly
dispersive applications (i.e. long fibers) where multimode lasers are inadequate.
For further information about semiconductor lasers, see [1] or the Ortel publication,
A System Designer's Guide to RF and Microwave Fiber Optics.
The microwave properties of a semiconductor laser are dependent on the bias
current for the device. As the bias is increased above threshold, the optical power
of the laser increases linearly. Most frequency dependent characteristics of the
laser, (noise, frequency response, distortion) scale with the square root of optical
power (or current above threshold). For example, if a laser exhibits a certain
bandwidth at a bias of 10 mA above threshold, the bandwidth will double when the
current is increased to 40 mA above threshold. There are some factors, such as
internal heating, which will slightly degrade the expected performance at higher
currents. Thus the actual scale factor will be slightly less than expected by the
square-root law. The bias current for the transmitters described in this manual are
factory set by Ortel to maximize the performance of the contained laser.
3.2
Optical Systems
The performance of most semiconductor lasers is affected by the optical system to
which it is connected. The first problem is optical reflections. A reflection can
destabilize laser performance, which is indicated by increased laser noise and, in
severe cases, distortion. Additionally, long fibers have a certain amount of light
reflected by impurities and imperfections in the fiber called backscatter. Both of
these problems are largely alleviated by, the optical isolator included in this
manual's transmitters. Another effect of long fiber is caused by dispersion. If the
laser is multimode, dispersion from long fibers (>5 km) can degrade noise,
distortion, and even bandwidth of the laser. The singlemode operation of DFB
lasers eliminates this problem.
[1] Agrawal, G.P. and Dutta, N.K., Long-wavelength Semiconductor Lasers, Van Nostrand Reinhold Company, New
York, New York, 1986.
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Ortel, a Division of Emcore
Fiberoptic Transmitters
3.3
Man-3540A Rev B
Temperature Control
For consistent operation of semiconductor lasers, the temperature of operation
must be maintained at some constant level. For this reason, all the lasers
described in the manual incorporate both a thermoelectric (Peltier) cooler and a
temperature-sensing resistor (thermistor). The transmitter includes a feedback
loop, which senses the thermistor resistance and compensates for changes in
laser temperature. The laser temperature is stabilized to 25°C ± 2°C.
As with the power control circuit, a current limiter prevents the TE cooler and laser
from damage due to excessive heating or cooling functions should the thermistor
fail.
3.4
Power Control
Over long periods of time, the laser chip will age slightly. In some applications,
precise control of the optical power received is required. In the transmitter, the
actual light output of the laser is sensed by the monitor photodiode, and a
feedback circuit maintains this monitor current at a constant level. Typically, the
laser power will remain stable to within ±2%. The power control circuit will not
compensate for changes in the laser/fiber coupling efficiency.
In addition to
the DC current supply circuit; there are two additional circuits in the optical power
control circuit. A "slow start" circuit operates when the transmitter is switched on.
This circuit increases the laser current over 3 seconds from zero to its operating
value. This eliminates transients, which could damage the laser. A current limiter,
preset at the factor, establishes a maximum value for the laser current. Thus, a
failure of the monitor photodiode will not result in uncontrolled laser current values,
which could destroy the laser.
3.5
External Displays and Controls
The fiberoptic transmitter needs no external controls or adjustments. The laser
current is preset at the factory to provide optimum performance according to the
specifications published in the data sheet and the Product Specification Table.
3.5.1 LED Displays
There are three external visual LED displays that provide information about
the operating state of the transmitter. These LED's are normally on. If any
of the LED's is off after applying DC power to the transmitter and waiting
for a few seconds, recheck all power connections. If the condition persists,
consult with Ortel's Customer Service department.
Power On: This LED is normally ON, and indicates that +15 V is present
at Pin #1 of the DC 9-pin connector.
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Ortel, a Division of Emcore
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Man-3540A Rev B
Laser Power Stable: This LED is normally ON, and indicates that the
laser optical power, as measured by the internal
monitor photodiode, is above 90% of the factory
preset value.
Laser Temp Stable: This LED is normally ON, and indicates that the
laser substrate temperature (as determined by the
thermistor resistance) is within ±2° C of the factory
setpoint. The transmitter may require several
seconds of operation before the LED goes on. If
the temperature does not stabilize, refer to section
4.3.1.
3.5.2 Status Monitors
Two monitor voltages are available on the DC connector. They are
designed to provide information about the operating condition of
internal optical power circuits for routine operational maintenance.
PIN 6: Photodiode Current. 1 V/mA, ±2% (1.0 MΩ load). Provides
a buffered voltage proportional to the monitor photodiode
current. Measuring and recording this voltage provides a
record of the laser output power over time, as measured by
the photodiode.
PIN 8: Laser DC Current. 1 V/100 mA, ±2% (1.0 MΩ load).
Provides a buffered voltage proportional to the laser DC
current. Measuring and recording this voltage provides a
record of the laser current over time.
3.5.3 Alarm Functions
In addition to the LED visual displays of transmitter operational
status, there are two alarm circuits in the transmitter, which can be
used to drive remote indicators. They are designed to provide a
positive interrupt capability if the laser transmitter drifts out of
factory set operating conditions, but before the laser fails
completely. This provides the capability of replacing or servicing
the unit before the link operation is interrupted.
The alarms are designed to interface with user-supplied circuits.
Alarms are open collector outputs capable of sinking 20 mA when
ON and withstanding 15 VDC when OFF. Normal operation of the
alarm circuit is the off state. A suggested use of the alarm circuit
would be a series connection of an external LED, or a relay, from
the system 15 V supply through a 1 kΩ resistor. Assuming
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Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
negligible voltage drop through the LED or relay, this would provide
a 15 mA activation current when the alarm is active.
The alarm functions and pin assignments are as follows:
PIN 7: Low Optical Power. This alarm is ON (sinks current) if the
laser monitor photodiode current drops from its factory set
value by more than 10%. The alarm is not activated if the
photocurrent is HIGHER than the setpoint.
PIN 9: Laser Temperature. This alarm is ON (sinks current) if the
laser substrate temperature is more than 2°C higher than
the factory setpoint. The alarm is not activated if the
temperature is LOWER than the setpoint.
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Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Chapter 4
4.0
Installation
The information in this section can be used to make initial performance tests on the laser
transmitter. It is not intended as a complete performance verification procedure.
4.1
Unpacking and Visual Inspection
ESD Sensitive Device
The laser transmitter was inspected before shipment and found to be free of
mechanical and electrical defects. Observe ESD precautions while handling the
transmitter and unpack and examine the device for any damage due to transit.
Keep all packing materials until your inspection is complete. Verify that the pins
and connectors are free from obvious shipping or handling damage.
If damage is discovered, file a claim with the carrier immediately. Notify the Ortel’s
Sales Department as soon as possible.
4.2
Operating Conditions
This product is designed and tested to withstand harsh environmental operating
and storage conditions. The basic design and manufacturing processes have
been subjected to rigorous product qualification tests of temperature cycling,
mechanical shock, and vibration. However, the device can be permanently
damaged by severe mechanical shock. Please handle carefully while unpacking
and installing.
Flange-mount
Plug-in
Operating Temperature
of Baseplate
-40 °C to +65°C
0 °C to 50 °C
Storage Temperature
-40 °C to +85 °C
-20 °C to +65 °C
To operate either style of transmitter at room temperature in a laboratory setting, it
can be placed on a convenient flat surface without any particular concern for a
good heatsink. In a field-operating environment, to obtain reliable operation over
the full temperature range, flange-mount transmitters should be fastened to a solid
metallic surface with a good heat sink using screws through the mounting holes
provided. Plug-ins should be installed in the Ortel Model 10990A Chassis and
provided a clear opening at the top and bottom to allow convection cooling.
18
Ortel, a Division of Emcore
Fiberoptic Transmitters
4.3
Man-3540A Rev B
Electrical Connection
Observe the following procedures while making electrical connection to the
transmitter.
4.3.1 DC Connection
DANGER: Connecting the transmitter to its appropriate DC voltages will
energize the laser and emit light from the fiber. This light is
invisible and may be harmful to the human eye. Avoid looking
directly into the fiber pigtail or into the collimated beam along its
axis when the device is in operation. Operating the laser diode
outside of its maximum ratings may cause device failure or a
safety hazard.
4.3.1.1 User-supplied Power Supply
Connect the transmitter to the required DC voltages using a
standard 9-pin DSUB connector.
The transmitter contains
internal regulator and transient suppression circuits. Most high
quality power supplies will provide excellent results, although at a
minimum the power supply must provide the following:
Pin #
Min.
Nom.
Max.
Max. Ripple
Current
1
+14 V
+15 V
+16 V
100 mV p-p
0.3 A max.
2
+4.75 V
+5 V
+5.5 V
200 mV p-p
1.5 A max.
For best results, make the DC connection to the transmitter and
verify that the power supply is correctly adjusted before switching
on the supply. When turning the transmitter on, there is a "slow
start" circuit that introduces a 2 to 3 second delay in the turn on.
When the LED's are all lit, the transmitter is ready to use. If the
laser temperature fails to stabilize, verify that the current capability
of the 5 Volt supply exceeds 1.5 Amps.
CAUTION:
Do not solder wires directly to the pins of the DC
connector.
The reference ground provides a separate ground path for more
accurate use of the monitor and alarm circuit, although it may be
connected to pin 4 and then the two used together as a common
ground.
19
Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
9 Pin D-sub
Connector
Corresponding 5 Pin
Connector (P11-P18)
on 10990A Chassis
1
--
+15 V DC, 0.3 A
2
--
+5 V DC, 1.5 A
3
--
NC
4
--
power ground
5
1
reference ground
6
2
photodiode current monitor
7
3
low optical power alarm
(open collector output)
8
4
laser current monitor
9
5
over temperature alarm
(open collector output)
Function
4.3.1.2 Ortel Model 10990A Chassis and 10901A/B Power Supplies
Plug-in style units may be used with an Ortel provided rack mount
chassis (Model 10990A), main power supply (Model 10901A), and
optional auxilary power supply (Model 10901B). With these
products, simply slide the transmitter into any slot in the chassis.
Blind-mate connectors on the back plane are wired to the power
supplies. Transmitters and receivers may be inserted with the
power supply turned on or off, although it is recommended that
the power supplies be plugged into a wall circuit to guarantee a
good ground. Due to power limitations, at most 4 transmitters or
8 receivers should be used in a single chassis.
The status of the plug-ins can be monitored on the back panel of
the chassis. The 8-transmitter/receiver slots each have a 5 pin
connector directly connected to the 9 pin D-sub. The power
supplies status can be monitored from the 9 pin Molex connector
(P19) which is wired into a series of relays.
20
Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Model 10990A Chassis Power Supply Status Connector (P19)
Pin
Description
Main OFF
Main ON
1
No connection
2
No connection
3
Aux. Status
4
Aux. Status
(center)
5
Aux. Status
6
Main Status
(center)
7
Main Status
closed
open
8
Main Status
open
closed
9
Ground
Aux. OFF
Aux. ON
closed
open
open
closed
Mating Connector
Molex P/N 22-01-2097
Crimp Pins
Molex P/N 08-50-0114
The voltages from the main power supply may be monitored and used directly with
connector P20.
Model 10990A Chassis, Main Power Supply Status Connector (P20)
Pin
Description
1
+5 V DC
2
+15 V DC
3
-15 V DC
4
GND
Mating Connector
Molex P/N 09-50-3031
Crimp Pins
Molex P/N 08-50-0108
21
Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
4.3.2 Optical Connection
DANGER: The light emitted from Ortel transmitters is invisible and may
be harmful to the human eye. Avoid looking directly into the
fiber pigtail or into the collimated beam along its axis when the
device is in operation.
When inserting light into a receiver, if optical connector is used,
repeatable performance requires that the connector end surface be kept
free of dirt and dust. Before mating, clean with a cotton swab and
alcohol, and blow dry with a lint free aerosol air spray. Many high quality
connectors use keying polarity, and it is important to observe such mating
requirements.
Should the internal connector of a bulkhead connector become dirty, the
mating sleeve assembly must be removed. This is accomplished by
removing the small setscrews and gently sliding the assembly out of the
receiver a few inches. The connector will still be connected to the mating
sleeve and can then be loosened and cleaned.
Some connectors can be improved by the use of index matching fluid,
although in most cases this is not used. Consult with the connector
manufacturer or Ortel for recommendations regarding specific
connectors. In general, tighten the connectors finger tight. Do not use a
wrench, as it will cause excessive optical loss and can damage the
connector end faces.
If a non-connectorized fiber option is provided, the fiber tip must
cleaved well and the tip must be clean. If not properly cleaved
cleaned, optical power may be scattered and the insertion loss may
high.
For temporary splices, the use of index matching fluid
recommended to reduce reflections.
be
or
be
is
For best performance, optical reflections should be minimized below -35
dB. Optical reflections can destabilize the laser diode, creating unwanted
noise and distortion.
4.3.3 RF Connection
CAUTION: RF power applied to an unbiased laser may damage the
device, therefore apply RF power only after DC power has
been supplied to the transmitter and always disconnect the
RF power before disconnecting the DC power.
22
Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Connect the RF signal source to the SMA input connector. Absolute
maximum signal level shall not exceed 100 mW (+20 dBm) at the risk of
damaging the laser diode.
CAUTION: Do not apply excessive torque to the SMA connector. The
use of standard wrenches can lead to a damaged connector.
Use 7 to 9 inch pounds of torque. The use of a torque
wrench is strongly recommended.
The input impedance of the transmitter is 50Ω. Use signal sources with
the same characteristic impedance.
CAUTION: The standard laser transmitters are AC coupled with an
internal DC blocking capacitor on the RF input. If the product
has been ordered without a DC blocking capacitor (Option
001), there can be effects on the test equipment due to the
DC voltage present at the RF connector, or, conversely, a
change in the bias point of the laser due to the DC
characteristics of the test equipment. If possible, for Option
001 it is recommended to use a DC blocking network, such
as the 5500 series provided by Picosecond Pulse Labs (303443-1249, Boulder, CO, USA).
4.3.4 Optical Power
CAUTION: These laser transmitters can deliver optical powers into the
fiber which are high enough to saturate or damage some
optical receivers. Generally, some optical attenuation is
needed to prevent performance degradation. This
attenuation can be provided by a long fiber length or by
inclusion of an intentional optical loss. See the Product
Specification Table, the test data, and the specifications of
the photodiode to determine the amount of attenuation
needed.
4.3.5 General Considerations
The maximum input power level is dependent on the laser bias point: if
the laser is biased at 50 mA above threshold, the maximum power input
to the laser before clipping is approximately +18 dBm. Beyond this point
laser damage may occur due to reverse biasing of the laser junction.
23
Ortel, a Division of Emcore
Fiberoptic Transmitters
4.4
Man-3540A Rev B
Initial Turn On Procedure
For initial operation of the transmitter, the use of a simple test circuit as shown in
Figure 4.1 is recommended. A fiberoptic receiver of sufficient bandwidth is
required to convert the optical signal to electrical form. Because of their superior
operating characteristics for analog signals, the use of Ortel receivers is
recommended. Choose a bandwidth that matches the frequency range of the
transmitter.
The recommended test equipment for an initial evaluation is as follows:
Description
Signal Generator
Range
Preset To
0.01 to 15 GHz
-10 to 10 dBm
1 GHz
0 dBm
Power Supply - 2 way
+15 V, +5 V
Spectrum Analyzer
0.01 to 15 GHz
1 GHz
1300 nm/1550 nm
0 to 5 mW
Optical Power Meter
Amplifier (optional)
30 dB gain
1 GHz
Fiberoptic Receiver
Same as transmitter
Digital Voltmeter
0 to 10 V
Since the link insertion loss (including an optical attenuator to limit the optical
received power to 2mW) is approximately 40 dB, an amplifier improves the
measurement by raising the signal level to the spectrum analyzer. An amplifier
is usually required to measure the output noise floor of the link. The amplifier is
usually not required to make basic operating measurements of the link, since
most spectrum analyzers will easily display signal levels of -40 dBm, which is the
expected output power from a link with 0 dBm input level.
4.4.1 DC Operation
Using grounded, shielded cable for power supply connections, verify that
the cables are correctly wired and that power supplies are properly
adjusted before applying power.
Switch on the power supplies
simultaneously to the transmitter and receiver. Verify that the LED's are
lit. If one or more of the LED's are not lit, double check the power supply
connections. If the trouble persists, contact Ortel Customer Service for
advice.
24
Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
When the transmitter is operated at room temperature, it will draw only
limited current (approximately 50 mA) from the +5 V supply, since the
thermoelectric cooler will be drawing minimal current.
If an Ortel receiver is in use, Pin 6 of the receiver DC connector provides
a simple indication of the optical power reaching the receiver. (If a plugin receiver is used, pin 6 connects directly to pin 2 of the 5-pin connector
on the back panel.) The proportionality factor is 1 V/mA of receiver
photocurrent. Typically, 1 mW of optical power will result in 0.7 to 0.8 mA
of photocurrent, resulting in a measured voltage of 700 to 800 mV.
If an Ortel receiver is not in use, use an optical power meter to verify that
the optical output power of the transmitter meets specifications.
4.4.2 RF Operation
Preset the signal generator to 1 GHz at 0 dBm, or to some convenient
frequency within the operating range of the transmitter. It is advisable to
calibrate the signal generator and spectrum analyzer by making a direct
connection to set a zero dB reference measurement level.
Apply the signal to the transmitter and measure the output of the receiver
on the spectrum analyzer. Verify that the output signal is clean with no
amplitude jitter or spurious signals.
Measure the power level of the receiver output. The gain of the fiberoptic
link will depend on the receiver characteristics, as well as the optical loss
of the test cable. For short cables (<100 meters) and good quality
connectors, and with an Ortel receiver, the link insertion loss should be
approximately 40 dB. Variations of ±5 dB in this value can occur and
should not be considered unusual.
Adjust the input power up and down by 3 to 4 dB and verify that the
receiver output tracks the input power linearly. If the spectrum analyzer
has sufficient bandwidth, measure the amplitude of the second harmonic
as a function of input signal power. The second harmonic power should
vary as 2:1 relative to the input power, indicating normal linear operation
of the transmitter.
There are three types of measurement equipment used for lasers:
Spectrum analyzer: noise and distortion
Network analyzer: frequency response
Oscilloscope: time domain and transient response
The measured frequency response of the laser necessarily includes the
response of the photodetector. In the factory, Ortel uses calibrated
receivers to reduce measurement errors due to the detector.
25
Ortel, a Division of Emcore
Fiberoptic Transmitters
4.5
Man-3540A Rev B
Performance Verification Procedure
The following procedures are based on the factory test procedure.
4.5.1 Frequency Response
In this manual the frequency response of the laser transmitters is
measured by, measuring the response of the transmitter, a calibrated
photodiode, RF cables, and correcting for the photodiode and cable
response. The first step is to measure the frequency response of the
measurement system (see Figure 4.1) including cables. The sweep
oscillator should be set to a nominal output power of +5 dBm. This
response is then stored. The transmitter and calibrated PD are then
inserted into the link. The link response is now measured using the inputmemory mode. The resulting curve represents the frequency response
of the transmitter.
4.5.2 VSWR
The Voltage Standing Wave Ratio characterizes the RF reflections from a
microwave component.
It can be determined by measuring the
microwave return loss or S11. A system for making this measurement is
shown in Figure 4.1. The network analyzer is pre-calibrated using the
open/short/load routine. This calibration is usually stored continuously in
memory.
4.5.3 Noise Measurements
There are two related but separate measures of the noise performance of
a laser: Equivalent Input Noise (EIN) and Relative Intensity Noise (RIN).
The equivalent input noise of a laser is equal to the noise that would be
observed if the laser itself generated no noise and a noise source
generating an equivalent amount of electrical noise was connected to the
input of the laser. In a hypothetical link, one in which the laser is the only
source of noise, if a signal that is x dB larger than the EIN level is injected
into the transmitter, the output signal of the link will be x dB above the
noise floor that is observed in the absence of an input signal. The RIN of
a laser is a similar measure of laser performance but relates the DC
optical power of the laser to the optical power fluctuations (noise).
RIN =
< ∆ P2 >
P
2
In practice, these measurements are made at several fixed frequencies.
26
Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
A.
EIN Measurement:
In a real link, the laser is not the only noise source;
therefore corrections must be made for other noise
sources. The system for making EIN measurements is
shown in Figure 4.2. For the standard transmitter, the
photodiode used must have an optical return loss of at
least 45 dB. To determine EIN, three measurements must
be made.
A signal at a power level of Y dBm (Y ≤10 dBm) is injected
into the laser transmitter. The output signal level (Z dBm)
is measured and recorded.
With no RF input signal, the link output noise floor in a
3 MHz resolution bandwidth is measured with a 10 kHz
video filter bandwidth. This measures the noise from the
laser and from the receiver.
With the laser turned off, the link output noise floor in a
3 MHz resolution bandwidth is measured and recorded.
This measures the noise from the receiver. (Measurement
C)
The EIN (per 1 Hz) is given by:
Y(mW)
EIN(mW / Hz)=
Res BW(Hz)*
Z(mW)
Output noise due to laser(mW)
The link output noise due to the laser is obtained by
subtracting the receiver noise (measurement C) from the
laser plus receiver noise (measurement B).
In the
presence of noise fluctuations due to reflections and
dispersion, the noise level is generally defined to be the
highest noise level that is observed on the spectrum
analyzer in the frequency band. A convenient method to
calculate this is to use correction factors as described
below:
EIN(dBm / Hz) = Y (dBm) -
27
Z
(dB) - 65 - ∆
(Output noise)
Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
where ∆ 3 is given in the table below:
Difference between curves
from B and C
∆4
1.0 dB
7.0
2.0 dB
4.0
3.0 dB
3.0
4.0 dB
2.0
5.0 dB
1.5
7.0 dB
1.0
10.0 dB
0.5
>10.0 dB
0
If the difference between curves B and C is less than 1 dB,
the measurement is not a valid measurement of laser
noise. More low noise amplification is needed after the
test photodiode.
B.
Relative Intensity Noise:
For this measurement, you need the data measured above
and you need to have a calibrated photodiode without RF
impedance matching. The following characteristics need
to be known at the frequency of measurement:
The gain of the amplifier G a 5 (Figure 4.2)
The loss of the photodiode
L pd 6 (relative to DC)
The photodiode current in mA
I pd 7
The noise power in dBm at the amplifier output from as
in A.
To actually derive the RIN, calculate:
- 10 log (I2pd* 50) - 30
28
(in dB/Hz)
Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Figure 4.1: Frequency Response, VSWR
Figure 4.2: EIN; RIN
29
Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Product Specification Table
Model 3541A/B/C
The following specifications describe the guaranteed performance that will be obtained under
the specified operating conditions, listed below, with the exception of typical (typ.) values,
which describe expected but not guaranteed performance.
1.0
Product Options
Option #
-001
-005
Description
DC-coupled RF output
1.5 x optical isolator
Optical cable options
2.0
Option #
Connector
Style
Cable
Available in
Flange-mount
Available in
Plug-in
-020
FC/APC
bulkhead
x
x
-021
FC/SPC
bulkhead
x
x
-022
FC/APC
3 mm diam.
x
-023
FC/SPC
3 mm diam.
x
-026
FC/PC
bulkhead
x
-028
FC/PC
3 mm diam.
x
x
Operating Conditions
Optical Return Loss of User's Fiber > 35 dB
RF Source Impedance
50 Ω
Flange-mount
Plug-in
Operating Temperature
of Baseplate
-40°C to +65°C
0 °C to 50°C
Storage Temperature
-40°C to +85°C
-20°C to +65°C
30
Ortel, a Division of Emcore
Fiberoptic Transmitters
3.0
Man-3540A Rev B
RF Parameters
PACKAGE STYLES
Flange-mount
3540A
3541A
3541B
3541C
3740A
3741A
Plug-in for 19" rack
10340A 10341A
10341B
10341C
10370A 10371A
RF PARAMETERS
Max. Freq. (GHz)
5
10
13
15
4
10
Min. Freq. (GHz)
0.1
0.1
0.1
0.1
0.1
0.1
option -001 (GHz)
0.01
0.01
0.01
0.01
0.01
0.01
Amplitude Flatness (dB)
±2
±2.5
±3
±3
±2.5
±2.5
±3
±3
±3.5
±3.5
±3
±3
Input VSWR (0.1 GHz to Max)
1.8 : 1
1.8 : 1
2.5 : 1
2.5 : 1
1.8 : 1
1.8 : 1
Input 1dB comprsn.,typ. dBm)
13
13
20
20
13
13
0.1/0.01 to 2.5 GHz
30
35
35
35
28
23
2.5 to 4 GHz
22
30
30
30
28
23
4 to 5 GHz
22
25
25
25
23
25
25
25
23
25
25
option -001 (dB)
Input Third Order Inter., (dBm)
(2 tone test)
5 to 10 GHz
10 to 13 GHz
13 to 15 GHz
25
Equiv. Input Noise (dBm/Hz)
0.1/0.01 to 1 GHz
-130
-130
-130
-130
-118
-118
1 to 2.5 GHz
-126
-130
-130
-130
-118
-118
2.5 to 3 GHz
-115
-130
-130
-130
-118
-118
3 to 4 GHz
-115
-125
-125
-125
-118
-118
4 to 5 GHz
-115
-125
-125
-125
-118
5 to 6 GHz
-125
-125
-125
-113
6 to 10 GHz
-120
-120
-120
-113
-115
-115
10 to 13 GHz
13 to 15 GHz
-115
Input Impedance 50 Ohms
RF connector SMA, female
31
Ortel, a Division of Emcore
Fiberoptic Transmitters
4.0
Man-3540A Rev B
Optical Parameters
PACKAGE STYLES
Flange-mount
3540A
3541A
3541B
3541C
3740A
3741A
Plug-in for 19" rack
10340A
10341A
10341B
10341C
10370A
10371A
1310±30
1310±30
1310±30
1310±30
1550±30
1550±30
Spectral Width, typ. (MHz)
no RF input
10
10
10
10
10
10
Optical Power, min. (mW)
4
3
3
3
3
3
DC Modulation Gain, min
(mW/mA)
0.10
0.06
0.06
0.06
0.05
0.05
0.1/0.01 to 1 GHz
-149
-149
-149
-149
-137
-137
1 to 2.5 GHz
-145
-149
-149
-149
-137
-137
2.5 to 3 GHz
-134
-149
-149
-149
-137
-137
3 to 4 GHz
-134
-144
-144
-144
-137
-137
4 to 5 GHz
-134
-144
-144
-144
-137
5 to 6 GHz
-144
-144
-144
-132
6 to 10 GHz
-139
-139
-139
-132
-134
-139
OPTICAL PARAMETERS
Wavelength (nm)
Relative Intensity Noise, max
(dB/Hz), no RF input
10 to 13 GHz
13 to 15 GHz
-139
Optical Power Stability
(at constant Monitor PD Current, laser temperature) ±15%
Fiber core/cladding 9/125 µm (Standard singlemode, SMF-28 compatible)
5.0
DC Parameters
Pin
Min
Nom
Max
Max Ripple
Max Current
1
+14 V
+15 V
+16 V
100 mV p-p
0.3 A
2
+4.75 V
+5 V
+5.5 V
200 mV p-p
1.5 A
32
Ortel, a Division of Emcore
Fiberoptic Transmitters
6.0
Man-3540A Rev B
Maximum Ratings
RF Input Power
+20 dBm/60 sec
ESD Sensitivity
(Using Human Body Model,
150 V RF pin; i.e. 200 pF
capacitor discharged
through 1.5 kΩ resistor).
500 V DC pin
Peak Reverse Laser Voltage
1V
33
Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Flange Mount Transmitter: Outline Drawing, Dimensions, and Pinouts
34
Ortel, a Division of Emcore
Fiberoptic Transmitters
Man-3540A Rev B
Plug-In Transmitter: Outline Drawing, Dimensions, and Pinouts
35
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