Thorlabs.com - Optical Spectrum Analyzers

Thorlabs.com - Optical Spectrum Analyzers
Thorlabs.com - Optical Spectrum Analyzers
OSA202 - October 3, 2016
Item # OSA201
OSA202 was discontinued on October 3, 2016. For informational purposes, this is a copy of the
Item # OSA201
website content at that time and is valid only for the stated product.
OPTICAL SPECTRUM ANALYZERS
► Dual-Function Broadband Spectrometer and Wavelength Meter
► Six Models Support Wavelengths from 350 nm to 12.0 µm
► Includes Windows ® Laptop with Pre-Installed Software
All OSAs Include Laptop with Our Data
Collection and Analysis Software
OSA202
600 - 1700 nm
FC/PC Input
OSA207
1.0 - 12.0 µm
FC/PC and Free-Space Inputs
OVERVIEW
Features
Six Models Optimized for Different
Spectral Ranges
OSA201: 350 - 1100 nm
OSA202: 600 - 1700 nm
Pre-Purchase Support
To help ensure that our OSAs will meet your
needs, we can provide the following:
OSA203B: 1.0 - 2.6 µm (10 000 - 3846 cm-1 )
OSA205: 1.0 - 5.6 µm (10 000 - 1786 cm-1 )
OSA206: 3.3 - 8.0 µm (3030 - 1250 cm-1 )
OSA207: 1.0 - 12.0 µm (10 000 - 833 cm-1 )
7.5 GHz Resolution (0.25 cm -1 ) in Spectrometer Mode (Click for Graph)
0.1 ppm Resolution in Wavelength Meter Mode (Sources with <10 GHz Linewidth)
Michelson Interferometer Acquires Spectrum via Fourier Transform
Includes Windows ® Laptop with Pre-Installed Software
Intuitive, Responsive, Flat Interface
Real-Time Math Operations, Unit Conversions, and Statistical Analysis
Libraries for LabVIEW™ and Common Programming Languages
Demo Units for Trial in Your Lab
Example Measurements
Evaluation of Suitability for Your Application
"Virtual Device" Software Demo (See Software Tab)
If you would like any of these services, please contact us with
your experimental requirements.
Thorlabs' Optical Spectrum Analyzers (OSAs) perform highly accurate measurements of the spectra of unknown light sources. These compact instruments suit
a wide range of applications, such as analyzing the spectrum of a telecom signal, resolving the Fabry-Perot modes of a gain chip, and identifying gas
absorption lines in a spectral measurement.
Many commonly available OSAs use grating-based monochromators, which have slow acquisition times due to the need to mechanically scan the grating and
average out noise at each wavelength. Thorlabs' OSAs acquire the spectrum via a Fourier transform using a scanning Michelson interferometer in a push/pull
configuration. This approach dramatically improves the acquisition time, enables a high-precision wavelength meter mode with ±1 part-per-million accuracy
(i.e., 7 significant figures), and allows the included software to provide robust statistical analysis of the acquired spectra. See the Design tab and the video to
the right for more information.
All of Thorlabs' OSAs are compatible with FC/PC-terminated fiber patch cables. Custom designs for other fiber input receptacles are available by contacting
Tech Support. In addition, except for the OSA201 and OSA202, Thorlabs' OSAs can directly accept a collimated free-space optical input with a Ø6 mm
maximum beam size, as detailed in the Free-Space Coupling tab. For wavelengths above 2 µm, we recommend single mode or multimode fluoride patch
cables with cores up to Ø100 µm.
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
The instruments are designed to measure CW light sources, and also work in some applications where a pulsed light
source is used; details may be found on the Pulsed Sources tab. Please contact Tech Support to discuss pulsed light
source applications.
To reduce the presence of water absorption lines in the mid-IR region of the spectrum, the OSA203B, OSA205, OSA206, and OSA207 feature two 1/4" ID
quick-connect hose connections on the back panel, through which the interferometer can be purged with dry air or nitrogen. Thorlabs' Pure Air Circulator Unit
is ideal for this task. Since none of the optics in our OSAs are made from hygroscopic materials, purging is not necessary to prevent water-induced
degradation of the cavity. An example spectroscopy setup is described in the Gas Spectroscopy tab above.
Our stock instruments are not designed for applications where it is necessary to recover small signals, including Raman spectroscopy and many fluorescence
experiments. If your application would benefit from increased detection sensitivity, please see the Custom OSAs tab for some of our capabilities.
Key Specifications
Please refer to the Specs tab for detailed specifications.
Quick Links
Item #
Wavelength Range
OSA201
350 - 1100 nm
OSA202
600 - 1700 nm
OSA203B
OSA205
Optical Inputs
FC/PC Connectora
1.0 - 2.6 µm b
Absolute Power mode is recommended for
narrowband sources. The OSA203B noise floor was
measured in low-temperature mode.
(10 000 - 3846 cm-1 )
1.0 - 5.6 µm
(10 000 - 1786 cm-1 )
FC/PC Connectora
Free-Space Input
3.3 - 8.0 µm
OSA206
(3030 - 1250 cm-1 )
OSA207
(10 000 - 833 cm -1 )
1.0 - 12.0 µm
Other Fiber Input Receptacles Available Upon
Request (See Custom OSAs Tab)
Specified in High-Temperature Mode
Power Density mode is recommended for
broadband sources. The OSA203B noise floor was
measured in low-temperature mode.
Hide Specs
SPECS
Item #
Wavelength Range
Level
Sensitivity b
Notes
OSA201
OSA202
Limited by
Bandwidth of
Detectors and
Optics
350 1100 nm
600 - 1700
nm
See Graphs Below
-60
dBm/nm
-70
dBm/nm
Spectral Resolutiond
Spectral Accuracy e
Spectrometer Mode
Wavelength Meter
Resolution
Display Resolutionh
Wavelength Meter
Accuracy e
OSA205
OSA206
1.0 - 2.6 µm a
(10 000 - 3846
1.0 - 5.6 µm
(10 000 - 1786
3.3 - 8.0 µm
(3030 - 1250
cm -1 )
cm -1 )
cm -1 )
-70
dBm/nmc
-40 dBm/nm
7.5 GHz (0.25 cm-1 )
See Graph Below
±2 ppm f
1 ppm f
Spectral Precision g
Wavelength Meter
OSA203B
0.1 ppm f
Wavelength Meter
Mode
(Linewidth < 10
GHz)
9 Decimals
±1 ppm f
0.2 ppm f
Wavelength Meter Precision i
CW Source
10 mW (10 dBm)
Input Damage Threshold j
-
20 mW (13 dBm)
Power Level Accuracy k
-
±1 dB
Optical Rejection Ratio
See the Design
Tab
30 dB
Input Power (Max)
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
-45 dBm/nm
OSA207
1.0 - 12.0 µm
(10 000 - 833 cm -1 )
-30 dBm/nm for 1.0 2.0 µm
-40 dBm/nm for 2.0 12.0 µm
Thorlabs.com - Optical Spectrum Analyzers
for Details
FC/PC Connectors l
All Single Mode Fiber Patch Cables, Including Fluoride SM Fiber Patch Cables
Standard and Hybrid Step-Index Multimode Fiber Patch Cables with ≤Ø50 µm Core and NA ≤ 0.22
Step-Index Fluoride Multimode Fiber Patch Cables with ≤Ø100 µm Core and NA ≤ 0.26
(Single Mode Patch Cables Provide the Highest Contrast)
Input Fiber Compatibility
-
Free-Space Input
-
Dimensions
-
320 mm x 149 mm x 475 mm
(12.6" x 5.9" x 18.7")
Input Voltagem
-
100 - 240 VAC, 47 - 63 Hz, 250 W (Max)
Operating Temperature
-
10 °C to 40 °C
Storage Temperature
-
-10 °C to 60 °C
Relative Humidity
-
<80%, Non-Condensing
Accepts Collimated Beams up to Ø6 mm
Red Alignment Laser Beam
Four 4-40 Taps for 30 mm Cage Systems
None
10 °C to 35 °C
a. Specified in high-temperature mode. In low-temperature mode, the wavelength range is 1.0 - 2.5 µm.
b. Minimum detectable power per nanometer using Zero Fill = 0 and the highest resolution and sensitivity settings.
c. Specified in low-temperature mode over 1.0 - 2.5 µm. In high-temperature mode, the level sensitivity is -65 dBm/nm over 1.0 - 2.6 µm.
d. Defined according to the Rayleigh criterion.
e. After a 45-minute warm-up, for a single mode FC/PC-terminated patch cable at an operating temperature of 20 - 30 ºC.
f. Specified in parts per million, which corresponds to nearly seven significant figures (depending on the specification). For instance, if the wavelength
being measured is 1 µm, the wavelength meter precision will be 200 fm.
g. Spectral Precision is the repeatability with which a spectral feature can be measured using the peak search tool.
h. Can be set from 0 - 9 decimals and has a feature that automatically estimates the relevant number of decimals.
i. Using the same input single mode fiber for all measurements.
j. Limited by the damage threshold of the internal components.
k. Specified using Absolute Power Mode, Zero Fill = 2, and Hann apodization, after a 45-minute warm-up, for an operating temperature of 20 - 30 °C.
(The different apodization modes available in the OSA software are described in section 16.2 of the manual.) The specified wavelength range is 400 1000 nm for OSA201, 600 - 1600 nm for OSA202, 1.0 - 2.4 µm for OSA203B, and 1.3 - 5.0 µm for OSA205, and the specification is valid for a single
mode FC/PC-terminated patch cable. For OSA206 and OSA207, the specified wavelength ranges are 3.3 - 8.0 µm and 2.0 - 11.0 µm, respectively,
and the specification is valid for collimated free-space beams with diameter < 3 mm and divergence < 3 mrad, assuming the included protective
window is installed in the free-space aperture.
l. Custom connectors for other fiber input receptacles are available upon request. Please contact Tech Support or see the Custom OSAs tab for details.
m. The OSA and the Windows ® laptop each come with a region-specific power cord.
Resolution and Sensitivity Specifications
The resolution shown here was calculated using the
formula explained in the Design tab. Although the
Absolute Power mode is recommended for
Power Density mode is recommended for
formula is valid for all OSA models, the usable
narrowband sources. Please note that the OSA203B broadband sources. Please note that the OSA203B
wavelength range of each model is limited by the
noise floor was measured in low-temperature
noise floor was measured in low-temperature
bandwidth of the detectors and optical coatings.
mode.
mode.
Data Acquisition Specifications
Time Between Updates
Sensitivity
Low Resolution
High Resolution
Low
0.5 s (1.9 Hz)
1.8 s (0.6 Hz)
Medium Low
0.8 s (1.2 Hz)
2.9 s (0.3 Hz)
Medium High
1.5 s (0.7 Hz)
5.2 s (0.2 Hz)
High
2.7 s (0.4 Hz)
9.5 s (0.1 Hz)m.
The scan sensitivity and resolution are two independent settings
controlled from the software. The sensitivity setting modifies the range
of detector gain levels, while the resolution setting changes the optical
path difference (OPD). For more details, see the Design tab.
Hide Design
DESIGN
Design
This tab describes the key concepts and implementation of the design used in Thorlabs' Optical Spectrum Analyzers.
Contents
Interferometer Design
Resolution and Sensitivity
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
Absolute Power and Power Density
Interferogram Data Acquisition
Interferogram Data Processing
Wavelength Meter Mode
Wavelength Calibration and Accuracy
Optical Rejection Ratio
Interferometer Design
Thorlabs' Fourier Transform Optical Spectrum Analyzer (FT-OSA) utilizes two retroreflectors, as shown
in the figure to the right. These retroreflectors are mounted on a voice-coil-driven platform, which
dynamically changes the optical path length of the two arms of the interferometer simultaneously and
in opposite directions. The advantage of this layout is that it changes the optical path difference (OPD)
of the interferometer by four times the mechanical movement of the platform. The longer the change in
OPD, the finer the spectral detail the FT-OSA can resolve.
After collimating the unknown input, a beamsplitter divides the optical signal into two separate paths.
The path length difference between the two paths is varied from 0 to ±40 mm. The collimated light
fields then optically interfere as they recombine at the beamsplitter.
Click to Enlarge
Schematic of the optical path in Thorlabs' OSA,
detailing the dual retroreflector design. We will refer
to this schematic throughout this tutorial.
The detector assembly shown in the figure to the right records the interference pattern, commonly referred to as an interferogram. This interferogram is the
autocorrelation waveform of the input optical spectrum. By applying a Fourier transform to the waveform, the optical spectrum is recovered. The resulting
spectrum offers both high resolution and very broad wavelength coverage with a spectral resolution that is related to the optical path difference. The
wavelength range is limited by the bandwidth of the detectors and optical coatings. The accuracy of our system is ensured by including a frequency-stabilized
(632.991 nm) HeNe reference laser, which acts to provide highly accurate measurements of beam path length changes, allowing the system to continuously
self-calibrate. This process ensures accurate optical analysis well beyond what is possible with a grating-based OSA.
Each OSA model has a spectral resolution of 7.5 GHz, or 0.25 cm-1 . The resolution in units of wavelength is dependent on the wavelength of light being
measured. For more details, see the Resolution and Sensitivity section below. In this context, the spectral resolution is defined according to the Rayleigh
criterion and is the minimum separation required between two spectral features in order to resolve them as two separate lines. These spectral resolution
numbers should not be confused with the resolution when operating in the Wavelength Meter mode, which is considerably better.
The Thorlabs FT-OSA utilizes a built-in, actively stabilized reference HeNe laser to interferometrically record the variation of the optical path length. This
reference laser is inserted into the interferometer and closely follows the same path traversed by the unknown input light field. To reduce the presence of water
absorption lines in the mid-IR region of the spectrum, the OSA203B, OSA205, OSA206, and OSA207 feature two quick-connect hose connections (1/4" ID) on
the back panel, through which the interferometer can be purged with dry air or nitrogen. Thorlabs' Pure Air Circulator Unit, which uses hosing that can be
directly inserted into these connectors, is ideal for this task.
Resolution and Sensitivity
The resolution of this type of instrument depends on the optical path difference (OPD) between
the two paths in the interferometer. It is easiest to understand the resolution in terms of
wavenumbers (inverse centimeters), as opposed to wavelength (nanometers) or frequency
(terahertz).
Assume we have two narrowband sources, such as lasers, with a 1 cm-1 energy difference,
6500 cm-1 and 6501 cm-1 . To distinguish between these signals in the interferogram, we would
need to move away 1 cm from the point of zero path difference (ZPD). The OSA can move ±4
cm in OPD, and so it can resolve spectral features 0.25 cm -1 apart. The resolution of the
instrument can be calculated as:
Click to Enlarge
OSA Resolution vs. Wavelength of the Unknown Input
The resolution shown here was calculated using the formula
to the left, using Δk = 1 cm -1 for Low Resolution Mode and
Δk = 0.25 cm -1 for High Resolution Mode. Although the
formula is valid for all OSA models, the usable wavelength
range of each model is limited by the bandwidth of the
detectors and optical coatings.
where Δλ is the resolution in pm, Δk is the resolution in cm-1 (maximum of 0.25 cm-1 for this
instrument) and λ is the wavelength in µm. The resolution in pm as a function of wavelength, converted using this formula, is shown in the graph to the right.
The resolution of the OSA can be set to High or Low in the main window of the software. In high resolution mode, the retroreflectors translate by the maximum
of ±1 cm (±4 cm in OPD), while in low resolution mode, the retroreflectors translate by ±0.25 cm (±1 cm in OPD). The OSA software can cut the length of the
interferogram that is used in the calculation of the spectrum in order to remove spectral contributions from high-frequency components.
The sensitivity of the instrument depends on the electronic gain used in the sensor electronics. Since an increased gain setting reduces the bandwidth of the
detectors, the instrument will run slower when higher gain settings are used. The figures below show the dependency of the noise floor on the wavelength and
OSA model.
The OSA is also designed so that it samples more points/OPD when the translation of the retroreflector assembly is slower. The data sampling is triggered by
the reference signal from the internal stabilized HeNe laser. A phase-locked loop multiplies the HeNe period up to 128X for the highest sensitivity mode. This
mode can be very useful when the measured light is weak and broadband, causing only a very short interval in the interferogram at the ZPD to contain all the
spectral information. This portion of the interferogram is normally referred to as the zero burst.
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
Noise Floor in Absolute Power Mode
Absolute Power mode is recommended for narrowband
sources. Note that the OSA203B noise floor was measured in
low-temperature mode.
Noise Floor in Power Density Mode
Power Density mode is recommended for broadband sources.
Note that the OSA203B noise floor was measured in lowtemperature mode.
Absolute Power and Power Density
The vertical axis of the spectrum can be displayed as Absolute Power or Power Density, both of which can be displayed in either a linear or logarithmic scale.
In Absolute Power mode, the total power displayed is based on the actual instrument resolution for that specific wavelength; this setting is recommended to be
used only with narrow spectrum input light. For broadband devices, it is recommended that the Power Density mode is used. Here the vertical axis is displayed
in units of power per unit wavelength, where the unit wavelength is based upon a fixed wavelength band and is independent of the resolution setting of the
instrument.
Interferogram Data Acquisition
The interference pattern of the reference laser is used to clock a 16-bit analog-to-digital converter (ADC) such that samples are taken at a fixed, equidistant
optical path length interval. The HeNe reference fringe period is digitized and its frequency multiplied by a phase-locked loop (PLL), leading to an extremely
fine sampling resolution. Multiple PLL filters enable frequency multiplication settings of 16X, 32X, 64X, or 128X. At the 128X multiplier setting, data points are
acquired approximately every 1 nm of carriage travel. The multiple PLL filters enable the user to balance the system parameters of resolution and sensitivity
against the acquisition time and refresh rate.
A high-speed USB 2.0 link transfers the interferogram for the device under test at 6 MB/s with a ping-pong transfer scheme, enabling the streaming of very
large data sets. Once the data is captured, the OSA software, which is highly optimized to take full advantage of modern multi-core processors, performs a
number of calculations to analyze and condition the input waveform in order to obtain the highest possible resolution and signal-to-noise ratio (SNR) at the
output of the Fast Fourier Transform (FFT).
A very low noise and low distortion detector amplifier with automatic gain control provides a large dynamic range, allows optimal use of the ADC, and ensures
excellent signal-to-noise (SNR) for up to 10 mW of input power. For low-power signals, the system can typically detect less than 100 pW from narrowband
sources. The balanced detection architecture enhances the SNR of the system by enabling the Thorlabs FT-OSA to use all of the light that enters the
interferometer, while also rejecting common mode noise.
Interferogram Data Processing
The interferograms generated by the instrument vary from 0.5 million to 16 million data points depending on the resolution and sensitivity
mode settings employed. The FT-OSA software analyzes the input data and intelligently selects the optimal FFT algorithm from our internal
library.
Additional software performance is realized by utilizing an asynchronous, multi-threaded approach to collecting and handling interferogram data through the
multitude of processing stages required to yield spectrum information. The software's multi-threaded architecture manages several operational tasks in parallel
by actively adapting to the PC's capabilities, thus ensuring maximum processor bandwidth utilization. Each of our FT-OSA instruments ships complete with a
laptop computer that has been carefully selected to ensure that both the data processing and user interface operate optimally.
Wavelength Meter Mode
When narrowband optical signals are analyzed, the FT-OSA automatically calculates the center wavelength of the input, which can be displayed in a window
just below the main display that presents the overall spectrum. The central wavelength, λ, is calculated by counting interference fringes (periods in the
interferogram) from both the input and reference lasers according to the following formula:
Here, m o is the number of fringes for the reference HeNe laser, m is the number of fringes from the unknown input, n o is the index of refraction of air at the
reference laser wavelength, n λ is the index of refraction of air at the wavelength λ, and λ o is the vacuum wavelength of the HeNe reference laser (632.991
nm).
The resolution of the FT-OSA operating as a Wavelength Meter is substantially higher than the system when it operates as a broadband spectrometer
because the system can resolve a fraction of a fringe up to the limit set by the phase-locked loop multiplier (see the Interferogram Data Acquisition section
above). In practice, the resolution of the system is limited by the bandwidth and structure of the unknown input, noise in the detectors, drift in the reference
HeNe, interferometer alignment, and other systematic errors. The system has been found to offer reliable results as low as ±0.1 pm in the visible spectrum and
±0.2 pm in the NIR/IR (see the Specs tab for details).
The software evaluates the spectrum of the unknown input in order to determine an appropriate display resolution. If the data is unreliable, as would be the
case for a multiple peak spectrum, the software disables the Wavelength Meter mode so it does not provide misleading results.
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
Wavelength Calibration and Accuracy
The FT-OSA instruments incorporate a stabilized HeNe reference laser with a vacuum wavelength of 632.991 nm. The use of a stabilized HeNe ensures longterm wavelength accuracy as the dynamics of the stabilized HeNe are well-known and controlled. The instrument is factory-aligned so that the reference HeNe
and unknown input beams experience the same optical path length change as the interferometer is scanned. The effect of any residual alignment error on
wavelength measurements is less than 0.5 ppm; the input beam pointing accuracy is ensured by a high-precision ceramic receptacle and a robust
interferometer cavity design. No optical fibers are used within the scanning interferometer. The wavelength of the reference HeNe in air is actively calculated
for each measurement using the Eldén formula with temperature and pressure data collected by sensors internal to the instrument.
For customers operating in the visible spectrum, the influence of relative humidity (RH) on the refractive index of air can affect the accuracy of the
measurements. To compensate for this, the software allows the assumed RH value to be set manually. The effect of the humidity is negligible in the infrared.
Optical Rejection Ratio
The ability to measure low-level signals close to a peak is determined by
the optical rejection ratio (ORR) of the instrument. It can be seen as the
filter response of the OSA, and can be defined as the ratio between the
power at a given distance from the peak and the power at the peak.
If the ORR is not higher than the optical signal-to-noise ratio of the source
to be tested, the measurement will be limited by the OSA's response,
rather than reflecting a true property of the tested source. The table to the
right provides an example.
Distance from 1550 nm Peak
Optical Rejection Ratio
0.2 nm (25 GHz)
30 dB
0.4 nm (50 GHz)
30 dB
0.8 nm (100 GHz)
30 dB
4 nm (500 GHz)
39 dB
8 nm (1000 GHz)
43 dB
This table provides the Optical Rejection Ratio at 1550 nm for the OSA203B with
the following settings: High Resolution, Low Sensitivity, Average = 4, Hann
apodization. All OSA models show similar behavior if the distance from the peak
is measured in GHz (units of frequency).
Hide Free-Space Coupling
FREE -SPACE COUPLING
Free-Space Coupling
Thorlabs' OSA203B, OSA205, OSA206, and OSA207 directly support free-space optical inputs. For the OSA201 and OSA202, we recommend using a
reflective collimator to collect the output from a fiber end. For details on both of these options, please read below.
OSA203B, OSA205, OSA206, and OSA207: Directly Compatible with
Free-Space Beams
The OSA203B, OSA205, OSA206, and OSA207 feature a built-in free-space optical input, allowing them to
directly accept collimated light beams. The maximum beam size is Ø6 mm, and the input aperture includes
four 4-40 taps for compatibility with our 30 mm cage systems. When the free-space door is open, a red
alignment beam is emitted that should be made collinear and antiparallel to the unknown input for optimal
measurement accuracy. For a demonstration, please refer to the video in the Overview tab at 2:54.
Free-Space Optical
Input Behind Door
Cage-Mounted
Polarizers in Front of
Free-Space Input
Since the interferometer assembly normally "floats" on gel bushings inside the case when using the fiber input, it is necessary to lock the interferometer to an
optical table surface when using the free space input. This can be accomplished by using the specially designed Ø1" pedestal posts included with the unit. By
securing these pedestal posts with a CF175 clamping fork, the interferometer is locked to the optical table, allowing for stable free-space measurements.
We recommend only using the posts supplied with the OSA to secure it to the optical table. Other posts, including our Ø1/2" optical posts, should not be used
to secure the OSA. Because the OSA weighs ~20 lbs (~10 kg), Ø1/2" posts will not provide adequate support. We also do not recommend using long optical
posts to raise the OSA off of the optical table surface.
Beam Height Adjustment
When the interferometer is locked to an optical table, the beam height is 61 mm (2.4") from the table surface. We recommend using a periscope assembly,
such as Thorlabs RS99 or one constructed with our DP14A damped post, to adjust the input beam height to that of the OSA's input.
Click to Enlarge
The underside of the OSA203B, OSA205, OSA206, and OSA207 has
M4-tapped holes that accept special optical posts included with the
unit. These posts can be secured to an optical table using two
CF175 clamping forks, which locks the OSA's interferometer to the
table surface, allowing for stable free-space measurements.
Click to Enlarge
OSA203B secured to an optical table and used to measure the freespace beam of a laser diode. The laser diode is mounted in an
LDM9T mount, and the beam is redirected by mirrors mounted in
POLARIS-K1 and KCB1 kinematic mounts.
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
OSA201 and OSA202: Use a Reflective Collimator
To send a free-space input into the OSA201 or OSA202, we recommend using a reflective collimator and a Ø50 µm core, 0.22 NA multimode fiber to collect
light and transport it to the instrument, as shown below. A single mode patch cable can also be employed to collect the light. This may provide more precise
results, but the alignment procedure is far more difficult (see Data Acquisition with a Single Mode Fiber Patch Cable, below, for details).
A list of parts used in this setup is available in the tables below. Mouse over the photo to see the corresponding part highlighted in the tables.
Item #
Description
Qty.
Item #
Description
Qty.
OSA202
Optical Spectrum Analyzer
1
UPH1.5
Ø1/2" Post Holder
1
M42L01
Ø50 µm Core FC/PC
Multimode Patch Cable
1
RC08FC-P01
LMR05
TR2
Reflective Collimator
1
Ø1/2" Fixed Optic Mount
1
Ø1/2" Optical Post
1
Item #
P6
Description
Qty
Ø1/5" Optical Post
1
1
1
PF05-03-P01
Ø1/2" Protected
Silver Mirror
2
C1513
Kinematic
V-Clamp Mount
POLARIS-K05
Ø1/2" Ultra-Stable
Mirror Mount
2
PM4
Large Adjustable
Clamping Arm
Ø1" Optical Post
2
Clamping Fork
2
RS3P8E
CF125
Basic Setup
Thorlabs' OSA can be used to study free-space light sources using a folding mirror pair and the RC08FC-P01 reflective collimator. In this
example, a 1532 nm HeNe laser is coupled into the OSA202 Optical Spectrum Analyzer.
Click to Enlarge
Coupling Equipment
The 1523 nm HeNe laser can be attached to the optical table using a P6 Ø1.5" post and a C1513 Kinematic V-Clamp Mount. The folding
mirror pair consists of two Ø1/2" PF05-03-P01 silver mirrors mounted in POLARIS-K05 mirror mounts. The Polaris mounts should be
Click to Enlarge
mounted on RS3P8E Ø1", 3" long posts held to the table with CF125 clamping forks. Mount the RC08FC-P01 reflective collimator using an
LMR05 fixed mount, a TR2 Ø1/2" post, and a UPH1.5 post holder. The beam height should be kept as low as possible in order to provide the best alignment
stability.
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
In this example, two output fibers were used: an M42L01 Ø50 µm core multimode FC/PC-to-FC/PC patch cable and a P1-SMF28E-FC-1 single mode FC/PCto-FC/PC patch cable. Initial coupling alignment should be conducted using the multimode fiber. Once the system is aligned for good coupling efficiency using
the multimode fiber, the MM patch cable can be replaced by an SM patch cable, if desired. The system will then need to be retweaked for optimal coupling
efficiency.
Alignment Procedure
Our HLS635 635 nm, 1 mW portable alignment laser, which is a battery-powered 635 nm laser source, can be used to roughly align the
system. At the start of the alignment, place both the HeNe laser and the reflective collimator at the same optical height as the folding mirror
pair; this will minimize the amount of vertical adjustment of the beam path needed.
Click to Enlarge
Mount the collimator and laser parallel to the hole pattern in the table. Plug the laser into the output fiber to run the light backwards through the system. Place
the first mirror onto the table so that the laser beam exiting the reflective collimator is incident on it at 45°, with the beam exiting the mirror parallel to the
optical table's holes. Then, place the second mirror similarly, so that the beam is indicent on the output aperture of the laser. At this point, the clamping forks
can be used to secure the post of each mirror mount to the table, and the system should be close to proper alignment.
Next, turn on the HeNe laser and view the two laser beams along the optical path using a VRC4 IR viewing card. Adjust the mirrors so that
the beams are incident on the same spot on the card at each point along the optical path. In the photo to the right, the small bright beam is
from the HeNe laser, while the large red beam is from the alignment laser, incident on the back side of the card.
Click to Enlarge
Next, measure the power of the free-space beam using the PM200 touch screen power meter and S122C sensor head. In this example, the
free-space power of the laser was measured to be 1.55 mW.
Click to Enlarge
Next, set up the PM200 power meter with the S155C fiber-coupled sensor to measure the output power in the fiber while the alignment of the
system is fine tuned.
Click to Enlarge
First, use the tip/tilt controls on one of the folding mirrors to find a maximum signal level. Next, turn the vertical adjustment screw on that
mirror mount a quarter-turn, and then use the other folding mirror to find the new maximum. If this power level is higher than the original maximum, then
continue this process until an absolute maximum is reached. If the power level was lower than the original level, repeat the same process, but turn the
adjustment screw on the first mirror mount in the opposite direction.
Repeat this process for the horizontal adjustment, and then iterate between horizontal and vertical adjustments until an absolute maximum power level is
reached. As shown by the final power measurement to the right, in this setup, a maximum coupling efficiency of ~80% was reached.
Data Acquisition
Finally, plug the M42L01 patch cable into the OSA to acquire data.
Click to Enlarge
Data Acquisition with a Single Mode Fiber Patch Cable
In some circumstances, using a single mode fiber patch cable may increase the accuracy of the OSA wavelength meter, due to reduced
variations in the optical path length inside the fiber. The alignment procedure is similar with single mode fiber, except that single mode fiber is Click to Enlarge
much more sensitive to errors in alignment. The system should be fully aligned using multimode fiber before switching to single mode fiber.
Much smaller adjustments should be made with the folding mirror pair during single mode alignment, and a lower coupling efficiency should be expected.
Here, a P1-SMF28E-FC-1 patch cable is being used to take data.
Results
Here is a screenshot of the OSA software taking data for this experiment. It shows the spectrum of the laser (top), as well as the OSA's
wavelength meter.
Click to Enlarge
The 1523 nm HeNe laser line corresponds to the 2s 2 → 2p 1 transition in Ne I, which has an energy corresponding to a vacuum wavelength of 1523.48765
nm*. In this example, the OSA202 measured a center vacuum wavelength of 1523.488 nm, which is within the specified ±1.5 pm accuracy of the OSA
wavelength meter.
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
* Information from the NIST Atomic Spectra Database.
Hide Software
SOFTWARE
Software for the Optical Spectrum Analyzer and CCD
Spectrometers
Software
Version 2.70
Each Optical Spectrum Analyzer includes a Windows ® laptop with our OSA software suite
pre-installed. This software features an intuitive, responsive, flat interface that exposes all
Includes a GUI for controlling the OSA, as well as a "virtual
functions in 1 or 2 clicks. We regularly update this software to add significant new
device" mode ideal for evaluating the software prior to purchase.
features and make improvements suggested by our users.
The software download page also offers programming reference notes for interfacing with
our Optical Spectrum Analyzers using LabVIEW™, Visual C++, Visual C#, and Visual
Basic. Please see the Programming Reference tab on the software download page for
more information and download links.
This software package is also compatible with Thorlabs' Compact CCD Spectrometers.
Software Highlights
The text below summarizes several key features of the OSA software suite. Complete details on the software are available from the manual (5 MB PDF).
Built-In Tools for Simple and Complex Analysis
The OSA software displays either the fast-Fourier-transformed spectrum or the raw
interferogram obtained by the instrument. In the main window, it is possible to average multiple
spectra; display the X axis in units of nm, cm-1 , THz, or eV; compare the live spectrum to
previously saved traces; perform algebraic manipulations on data; and calculate common
quantities such as transmittance and absorbance.
Robust graph manipulation tools include automatic and manual scaling of the displayed portion
of the trace and markers for determining exact data values and visualizing data boundaries.
Automated peak and valley tracking modules (see the screenshot to the right) identify up to
2048 peaks or valleys within a user-defined wavelength range and follow them over a long
period of time. Statistical parameters of traces such as standard deviations, RMS values, and
weighted averages are available, and a curve fit module fits polynomials, Gaussians, and
Lorentzians to the spectrum or interferogram.
Click to Enlarge
Peak Track Mode Used with 7.9 µm Quantum Cascade Laser
Acquired data can be saved as a spectrum file that can be loaded quickly into the main
window. Data can also be exported into Matlab, Galactic SPC, CSV, and text formats.
Click to Enlarge
Wavelength Meter Observes Mode Hopping of 3.392 µm HeNe
Adjustable Sensitivity and Resolution Settings
The scan sensitivity and resolution can be adjusted by the user to balance the needs of the
experiment against the data acquisition rate. These settings vary the number of data points per
interferogram from 0.5 million to 16 million. The sensitivity setting modifies the range of
detector gain levels, while the resolution setting controls the optical path difference (OPD). The
table in the Specs tab shows how the data acquisition rate depends upon the chosen settings.
Wavelength Meter Module for Narrowband Sources
For sources with <10 GHz linewidth, the Wavelength Meter module enables extremely accurate
Click to Enlarge
determinations of the center wavelength (±1 ppm accuracy, 0.2 ppm precision, and 0.1 ppm
Coherence Length and Power of 1550 nm Superluminescent
resolution). This mode allows the system to resolve a fraction of a fringe in the interferogram,
Diode (SLD)
using the phase-locked loop that is generated by the internal stabilized reference HeNe laser
(see Interferogram Data Acquisition in the Design tab for details). The uncertainty in the measurement is continuously determined and displayed as gray
numbers.
As shown in the image to the right, a built-in module plots the output of the wavelength meter measurement as a function of time. If the software determines
that the wavelength meter will give inaccurate results (as it would for broadband sources), it is automatically disabled.
Coherence Length Module for Broadband Sources
Because Thorlabs' OSAs obtain the raw interferogram of the unknown source (as opposed to grating-based spectrum analyzers, which cannot offer this
capability), the software is able to calculate the coherence length of the input signal, as shown by the screenshot to the right. The Coherence Length module
considers the envelope of the interferogram and reports the optical path length over which the envelope's amplitude decays to 1/e of its maximum value on
both sides.
The ability to view the raw interferogram in real time allows the user to confirm the coherence length reported by the software and adjust the signal amplitude
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
to avoid saturation. The maximum coherence length measurable by the OSA is limited by the maximum optical path difference of ±4 cm in high-resolution
mode, making this module best suited for broadband sources.
Apodization and Interferogram Truncation
Since the resolution of any Fourier-transformed spectrum is intrinsically constrained by the finite path length over which the interferogram is measured, the
software implements several functions to account for the effect of the finite path length on the spectrum that is obtained. The user may select from a number of
apodization methods (dampening functions), including cosine, triangular, Blackman-Harris, Gaussian, Hamming, Hann, and Norton-Beer functions, and the
effective optical path length can also be shortened to eliminate contributions from high-frequency spectral components.
Libraries for LabVIEW, C, C++, C#, and Java
Device interface libraries containing a multitude of routines for data acquisition, instrument control, and spectral processing and manipulation are also provided
with the instrument. These libraries can be used to develop customized software using LabVIEW, C, C++, C#, Java, or other programming languages. We also
provide a set of LabVIEW routines to assist with writing your own applications.
Spectroscopic Analysis from HITRAN Reference Database
In environmental sensing and telecom applications, it is often useful to identify atmospheric compounds (such as water vapor, carbon dioxide, and acetylene)
whose absorption lines overlap with that of the unknown source being measured. Some example measurements are shown below. The OSA software includes
built-in support for HITRAN line-by-line references, which can be used to calculate absorption cross sections as a function of vapor pressure and temperature.
The predictions can be fit to the measured trace for comparison, and fits using mixtures of gases are supported. See the Gas Spectroscopy tab for an example
setup.
Click to Enlarge
Experimentally Measured Water Absorbance in Mid-IR
Click to Enlarge
Carbon Dioxide (CO 2) Absorption Before and After Baseline
Correction
Hide Pulsed Sources
PULSED SOURCES
Analyzing Pulsed Sources Using the OSA
Introduction and Summary of Results
While Thorlabs' Optical Spectrum Analyzers (OSAs) have been designed for analysis of CW signals, it is possible to measure pulsed spectra under certain
situations. Measurement of pulsed spectra suffers from several issues that must be overcome for accurate measurements; for instance, "spectral ghosts"
arise due to the pulsed nature of the source as well as the varying optical path difference (OPD) of the OSA. In addition, the noise floor for pulsed sources
is much higher than that for CW sources. One method for measuring pulsed sources with the OSA involves taking several successive measurements at the
four different sensitivity levels; the minimum at each wavelength of these four traces is used to form a combined spectrum, which suppresses the spectral
ghosts. This technique is implemented in the OSA software by choosing "Pulsed" under the "Sweep" tab. The following tutorial explains the rationale of this
technique and the pulsed sources for which it is useful.
In summary, for pulse rates over 30 kHz, standard mode can be used because the repetition rate is greater than the detectors' bandwidth. For broadband
signals with low repetition rates, care must be taken to ensure that the "zero burst" of the interferogram coincides with one of the pulses. Also, when using
a pulsed source "Automatic Gain" does not work properly, so the user must monitor the interferogram and manually set the gain so that a strong, but not
saturated, signal is obtained.
Impact of a Pulsed Source on the Interferogram and Spectrum
As the Optical Path Difference (OPD) continuously changes during an interferogram measurement, a pulsed light source effectively modulates the
interferogram. In the case of 100% modulation (i.e. on-off pulsation), the resulting interferogram will contain repetitive regions (slots) with no information.
These slots correspond to OPDs when no light can be measured by the detector assembly. The resulting interferogram in this case is the true interferogram
masked with the pulsed signal. Figure 1 shows measured interferograms and the corresponding spectra for a light source in CW and pulsed operation.
Although the spectrum of the light source is expected to be the same for CW and pulsed operation (ignoring small changes in the peak shape and position due
to, for example, a decreased LD chip temperature resulting from the pulsed drive), additional frequency artifacts appear symmetrically about the expected peak
due to the modulation in the pulsed interferogram. These "spectral ghosts" are a result of the temporal, rather than the spectral, behavior of the source. To
measure the true spectrum of the light source, it is crucial to make the spectral ghosts sufficiently small or force the spectral ghosts to fall outside the
frequency / wavelength range of interest.
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
Figure 1: Measured interferograms and spectra for a narrowband light source in CW (Top) and pulsed at 20 kHz (Bottom) operation. The square wave
modulation of the interferogram induces the spectral ghosts shown in the bottom left plot.
Mathematically, the resultant spectrum of a pulsed source can be described by a convolution
between the spectrum of the light source and the spectrum corresponding to the pulses. As a
result, the impact of these artifacts will vary with the pulse repetition rate and the modulation
depth of the light source as well as the OPD sample rate (cm/s) of the OSA. The modulation
depth of the light source determines the amplitude of the spectral ghosts; a weak modulation
yields weak spectral ghosts while a modulation of 100% (on-off pulsation) yields the strongest
spectral ghosts.
Figure 2 shows how the behavior of the spectral ghosts as a function of the pulse repetition
Click to Enlarge
Figure 2: Stacked spectra for 55 pulse repetition rates
rate for a narrowband source. In the figure, the spectra were measured for 55 pulse repetition
between 100 Hz and 100 kHz for a 1550 nm DFB laser diode.
rates between 100 Hz and 100 kHz for a 1550 nm DFB laser diode. We have offset the y-axis
The intensity is mapped in a logarithmic scale. OSA settings:
such that the true peak (the light gray horizontal line) has been centered at a relative frequency High Resolution, High Sensitivity, No Apodization, 5 averages.
of 0 THz. The figure can be divided into three regions: f p ≤ 3 kHz, 3 kHz < f p ≤ 30 kHz and f p
>30 kHz. For f p ≤ 3 kHz, the spectral ghosts are clearly observed symmetrically about the true peak within the resultant spectrum, and move farther and farther
away from the true peak as the repetition rate increases. The second region starts above 3 kHz, when the first spectral ghosts have moved beyond the spectral
range of the OSA. However, aliasing / folding create higher order spectral ghosts that appear within the spectral range of the OSA. In the third region, f p > 30
kHz, the resulting spectrum agrees very well with the CW spectrum because the repetition rate of the source has extended beyond the bandwidth limit of the
detectors. As a result, the pulsed source appears like a CW source to the OSA electronics.
"Pulsed Mode" Operation
To help remove some of these frequency artifacts, the OSA software contains a "Pulsed Mode" measurement (Figure 3). The "slot period" of the interferogram,
determined by the pulse repetition rate of the light source and the OPD rate of the OSA, affects the positions of the spectral ghosts. A shorter slot period
yields a larger spectral distance between the true peak and the first order ghost peaks. In Thorlabs' OSAs, the OPD sample rate is given by the speed of the
moving carriage which can be controlled by the user indirectly through the sensitivity setting. The higher the sensitivity setting is, the speed of the moving
carriage will be slower. Thus, the use of the "High" sensitivity mode of the OSA will provide the shortest slot period (i.e. the largest spacing between the
feature of interest and the frequency artifacts). In pulsed mode, the software acquires four spectra with different sensitivity settings (or OPD sample rates) and
filters out the changing spectral features. The sensitivity is first set to low, followed by Medium-Low, Medium-High, and High before it again is set to Low
yielding a periodically changing sensitivity. The captured spectra are then combined using the minimum hold function. The spectral ghosts (Figure 4), whose
positions depend on the sensitivity setting (the OPD rate), can then be reduced in the measurement as shown in Figure 4. It is important to note that the Pulse
Mode button is found under the "Sweep" menu and can be started only after the current sweep has been completely stopped.
Click to Enlarge
Figure 3: Screenshot of the OSA software in the Pulsed
Mode; the icon is indicacted with a red circle.
Click to Enlarge
Figure 4: (Left) Measured Spectra for a narrowband light
source pulsed at 1 kHz with (from top to bottom) Low,
Medium-Low, Medium-High, and High sensitivity settings (i.e.
a decreasing OPD sample rate from top to bottom). (Right)
Measured spectrum using the Pulsed Mode, i.e., a minimum
hold combination of spectra similar to those shown in the
bottom left plots.
Narrowband Light Source
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
A DFB laser diode emitting at 1550 nm (193.7 THz) was used as a narrowband light source and measured with an OSA203 in both CW and pulsed operation.
The laser diode was modulated (using Thorlabs' ITC4001) with repetition rates between f p = 20 Hz and 100 kHz. Five averaged spectra were captured for each
light source setting; the CW spectra were acquired in high sensitivity mode, and the pulsed spectra were recorded in both high sensitivity and pulsed mode. It
is important to note that the pulsed mode does not allow averaging. Instead the minimum hold function was used for 5 sets of spectra from the four different
sensitivity settings.
Figure 5 shows the resultant spectra for the source in CW mode as well as four different pulse repetition rates between 100 Hz and 100 kHz. As the pulse rate
increases, the spectral ghosts (as recorded in the high sensitivity mode) move further and further away from the true laser peak until nearly identical spectra
are obtained at 100 kHz.
Figure 5: Spectra from measurements of a 1550 nm (193.7 THz) pulsed narrowband source. Pulse repetition rates shown (left to right): 100 Hz, 1 kHz, 13
kHz, and 100 kHz. Black line: CW measurement, blue line: pulsed source measured with high sensitivity, red line: pulsed source measured using the pulsed
mode. The lower plots are the same data set as the upper plots only on a shorter frequency scale.
Broadband Light Source
A gain chip was driven in amplified spontaneous emission (ASE) mode to create a broadband light source centered at 850 nm (352.9 THz) with a FWHM of
36.4 nm (15.2 THz). An OSA201 was used to measure the spectrum for CW and pulsed operation with pulse repetition rates from f p = 100 Hz to 100 kHz. The
ASE diode was modulated (using Thorlabs' ITC4001) with a 50% duty cycle square wave. A total of 10 averaged spectra were acquired using high sensitivity
(CW and pulsed sources) and the pulsed mode (pulsed source). Because pulsed mode does not allow averaging, the minimum hold function was used to
acquire five sets of the four different sensitivity settings.
In general, the spectral ghosts are less visible for the broadband peak compared to a narrowband peak. However, the noise floor is higher and the spectral
ghosts are clearly seen for a repetition rate of 1 kHz and 13 kHz in Figure 6. Similar to the narrowband source, the spectral ghosts move farther and farther
away from the true peak with increasing repetition rate. For a repetition rate of 100 kHz both the measurement using high sensitivity and pulsed mode agree
well with the CW measurement. As seen, the shape of the peak is slightly different for the CW spectrum compared to the pulsed spectrum. This is not related
to the behavior of the OSA but due to a true change in the peak during pulsed operation, e.g., a lower chip temperature.
Figure 6: Measured spectra from a pulsed broadband source with a center wavelength (frequency) of 850 nm (352.9 THz). The pulse repetition rates shown
are 100 Hz, 1 kHz, 13 kHz, and 100 kHz. Top and bottom rows show the full spectrum and the ±50 THz range surrounding the peak, respectively. Black Line:
CW; Blue Line: Pulsed source measured using high sensitivity; Red Line: Pulsed Mode.
It is extremely important to note that in general, one has to be careful when measuring broadband peaks at low repetition rates. Since most of the information
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
in the interferogram is located about the zero burst, the peak can be completely missed if the zero burst coincides with no light falling on the detector as shown
in Figure 7.
Figure 7: Measured interferograms (left) and spectra (right) obtained when the zero burst resulting from a broadband source coincides with a pulse (blue
curves) and is missed if no light reaches the detector at OBD ~ 0 (red curves).
Femtosecond Pulsed Laser
We measured the spectrum of a broadband femtosecond laser (Thorlabs' OCTAVIUS-85M-HP)
using an OSA201. This laser has a repetition rate of 85 MHz, a pulse width of 10 fs, and an
average power of about 300 µW into the fiber. The OSA was set to Low Resolution, High
Sensitivity, 5 spectral averages, and no apodization. Light output from the laser was collected
with an SM600 (0.12 NA, 4.6 µm mode field diameter at 680 nm) patch cable connected to the
OSA.
Figure 8 shows the interferogram collected during acquisition, which does not contain any
empty slots. This was expected as the 85 MHz repetition rate of the laser is well beyond the 40
kHz bandwidth of the OSA's detectors. Furthermore, the spectrum measured by the OSA
agrees very well with the reference spectrum captured using a grating-based OSA that is
scanned slowly enough to provide adequate signal for each wavelength measured.
Click to Enlarge
Figure 8: (Top) Central portion of a captured interferogram
from a broadband femtosecond laser. (Bottom) Measured
spectrum captured using an OSA201 (red line) and a
measured reference spectrum captured using a scanning
grating-based OSA (blue line).
Hide Gas Spectroscopy
GAS SPECTROSCOPY
Gas Detection and Identification Using
an Optical Spectrum Analyzer
Level Sensitivity
As shown in the table to the right, many of Thorlabs' Optical
Spectrum Analyzers (OSAs) offer detection extending into
the mid-infrared (MIR) region of the spectrum, where many
gaseous species characteristically absorb. Moreover, the
Click to Enlarge
Hose Connections for
software included with all OSA models supports files from
Purging OSA Cavity
the HITRAN database, a spectroscopic reference standard.
These files can be fit to measured traces to identify unknown gases. With the ability
to fit multiple analytes simultaneously and built-in hose connections (compatible with
Thorlabs' Pure Air Circulator Unit) for purging the interferometer's cavity of trace
gases, these OSAs are ideal for use in home-built gas detection setups.
Item #
Frequency Range
OSA207
833 - 10 000 cm -1
(12.0 - 1.0 µm)
OSA206
1250 - 3030 cm-1
(8.0 - 3.3 µm)
OSA205
1786 - 10 000 cm-1
(5.6 - 1.0 µm)
OSA203B
3846 - 10 000 cm-1
(2.6 - 1.0 µm)
(Click for Graph) a
Absolute Power
Power Density
Lower values of Level Sensitivity correspond to improved
detection sensitivity. We therefore recommend selecting the
OSA which provides the lowest level sensitivity for the
analytes you intend to study.
Experimental Setup
A sample detection setup is shown below. Broadband MIR light generated by a Stabilized Light Source is emitted from a zirconium fluoride fiber (
),
collimated, then sent into a multipass cell ( ) containing the gas analyte in a sample chamber. Each end of the chamber is sealed by an airtight, transparent
window. Gold mirrors on each side of the chamber provide multiple reflections that increase the sensitivity of the measurement; the mirror closer to the light
source has a center hole to allow the optical path to enter and exit the chamber. Light exiting the detection setup is collimated by a long-focal-length lens and
reflected by a D-shaped mirror into the free-space port of the OSA203B (
prevent the gas's absorption lines from shifting during the measurement.
). The temperature inside the chamber is elevated and held constant in order to
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
Click to Enlarge
A gas detection setup using the OSA203B. A multipass cell is constructed around the sample chamber (
provide high detection sensitivity for the gaseous species sealed inside.
Parts Used in Sample Setup
(Click Here for a Metric Item List)
Item #
Qty.
Description
SLS202L
1
Stabilized Fiber-Coupled Light Source, 450 nm - 5.5 µm
(Not Shown)
FB2000-500
1
Ø1" Bandpass Filter, 2.0 µm CWL, 0.5 µm FWHM (Not Shown)
MZ21L1
1
ZrF 4 Multimode Fiber Patch Cable, SMA905 Connectors
F021SMA-2000
1
SMA905 Fiber Collimator, AR Coated: 1.8 - 3.0 µm
Light Source
POLARIS-K1
1
Polaris™ Ø1" Kinematic Mirror Mount
AD11NT
1
Unthreaded Adapter for Ø11 mm Cylindrical Components
1
Optical Spectrum Analyzer, 1.0 - 2.6 µm
Detection
OSA203B
TC200
2
Temperature Controller
MB1218
1
12" x 18" Aluminum Breadboard
CF125C
3
Clamping Fork with Captive Screw
Other Optomechanics
RS2
6
Ø1" Pillar Post, Length = 2"
RS3
1
Ø1" Pillar Post, Length = 3"
RS4
2
Ø1" Pillar Post, Length = 4"
BA2F
9
Flexure Clamping Base
Parts Used in Sample Setup (Continued)
(Click Here for a Metric Item List)
Item #
Qty.
Description
Beam Path Into and Out of Multipass Cell
LB4374
1
Uncoated, Ø1", f = 1000 mm Bi-Convex UV Fused Silica Lens
CP02
1
Post-Mountable, SM1-Threaded Cage Plate for Ø1" Optics
CM750-200-M01
2
Ø75 mm, f = 200 mm Protected Gold Concave Mirror
(One Mirror Contains a Center Hole, Similar
to Our Herriott Cell Mirrors)
KS3
2
Kinematic Mount for Ø3" Mirrors
VPCH512
2
Ø2.75" ConFlat Flange with CaF2 Window, 180 nm - 8.0 µm
N/A
1
Sample Chamber
C1513
1
Kinematic V-Clamp Mount
PM4
2
Clamping Arm
(One Clamping Arm is Included with Each C1513 Mount)
P6
1
Ø1.5" Mounting Post, Length = 6"
PB2
1
Base for Ø1.5" Mounting Posts
PFD10-03-M01
1
1" Protected Gold D-Shaped Pickoff Mirror
KM100D
1
Kinematic Mount for 1" D-Shaped Pickoff Mirrors
MB624
1
6" x 24" Aluminum Breadboard
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
) in order to
Thorlabs.com - Optical Spectrum Analyzers
Assigning Peaks in an Unknown Spectrum
Once the experimental spectrum is obtained, the user chooses a gas or gas mixture that is believed to be present inside the sample chamber, as shown in the
figure below to the left. There is no limit to how many species can be considered in the fit, but the fit is more likely to converge when fewer species are
chosen. The OSA software ships with HITRAN line-by-line references for acetylene (C 2 H2 ), water vapor (H 2 O), and carbon dioxide (CO 2 ), and can import
additional references downloaded from the HITRAN database. Previously saved spectra in the OSA file format can also be used as references. See the
References section of the OSA manual for details.
The user may optionally allow the software to shift the reference spectrum in wavelength in order to account for measurement effects related to the sample
environment. In the case of gas mixtures (i.e., fits performed using more than one reference spectrum), the software scales the intensity of each reference as
needed to reproduce the measured spectrum. As shown in the figure below to the right, the output of the fit operation is a graph comparing the measured
spectrum, each scaled (and possibly also shifted) reference spectrum, and the sum of the scaled reference spectra.
Click to Enlarge
In the Reference Fit Setup tab, checkboxes are used to
indicate which gaseous species to consider in the fit. The
absorption lines can be either "fixed" or "free"; the latter
allows the software to shift the reference spectrum in
wavelength. The measurement conditions for the HITRAN
references are also displayed.
Click to Enlarge
In the Reference Fit Result tab, the fitted spectrum is
displayed simultaneously with the measured spectrum. The
fitted spectrum is the sum of the scaled reference spectra
included in the fit. The scaled spectrum for each individual
gaseous species is also shown.
Hide Custom OSAs
CUSTOM OSAS
Custom OSA Options
Optical Input
FC/PC, FC/APC, or SMA905 Fiber
Receptacles
Free-Space Input for Collimated Beams
Permanently Installed Optical Bandpass and
Notch Filters Before Interferometer
Click to Enlarge
Application-Optimized Detectors
A user requested an OSA capable of detecting
High Sensitivity for Low-Level Signal
photoluminescence from wafers that emit in
Detection, Such as in Fluorescence or Raman the 2 - 4 µm spectral range. We provided a
custom-built OSA with a greatly reduced noise
Measurements
floor as compared to the OSA205, which easily
Wavelength Range and Noise Floor Chosen
detected the predicted signal.
to Match a Specific Light Source
Custom Software Modules for Data Analysis
Click to Enlarge
At typical humidities, water absorption peaks
in the spectrum of Thorlabs' SLS202 light
source drop well below the noise floor of the
OSA205. For MIR applications that require
such peaks to be resolved, we have qualified
two MCT (HgCdTe) detector elements which
achieve significantly lower noise floors, in
exchange for a narrower wavelength range
and lower maximum input power.
Thorlabs' in-stock OSA models offer a number of detection options for various experimental situations. For customers whose needs are not addressed by these
models, we invite you to work with our engineering and manufacturing team to tailor an OSA to your specific application.
In the past, we have built OSAs with user-specified optical inputs, such as FC/APC fiber receptacles, SMA905 fiber receptacles, and free-space ports, and we
have incorporated optical bandpass and notch filters directly into the optical path to reduce light source noise. For customers who use these instruments for
sample characterization, our software team has implemented user-designed data analysis modules within the standard OSA software suite.
We have also worked with our customers to choose detector elements targeted at specific light sources and analytes. The graphs to the right were obtained
from custom-built OSAs that were designed for especially high detection sensitivity. Our engineers are well-versed in the tradeoffs between detection
bandwidth, sensitivity, and linearity, and can make recommendations based upon the needs of the application and prior customers' experiences. By
constraining the OSA's design for a particular use case, additional performance enhancements for that application can be realized.
If you would like to discuss a custom OSA, please contact us with your experimental requirements.
Hide Optical Spectrum Analyzer for 350 - 1100 nm
Optical Spectrum Analyzer for 350 - 1100 nm
350 - 1100 nm Wavelength Range Ideal for Visible and NIR Detection
FC/PC Fiber-Coupled Input
Noise Floor: -60 dBm/nm (Power Density Mode; See Design Tab for Details)
Includes Windows ® Laptop with Thorlabs' OSA Software Pre-Installed
Demo Units Available by Contacting Tech Support
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
Optimized for use in the 350 - 1100 nm spectral range, the OSA201 measures the optical power of both
narrowband and broadband sources as a function of wavelength. This spectral range is frequently used
Click to Enlarge
FC/PC Optical Fiber
Input
for absorption spectroscopy, material identification, and quality control. The maximum spectral resolution of 7.5 GHz (0.25 cm-1 ) is
set by the maximum optical path length difference of ±4 cm, as explained in the Design tab, while the high spectral accuracy of ±2
ppm (parts per million) is ensured by simultaneously measuring the interferogram of a stabilized 632.991 nm HeNe laser. For
sources with linewidth < 10 GHz, enabling the Wavelength Meter mode provides 0.1 ppm resolution and ±1 ppm accuracy.
Fiber-Coupled Input
The OSA201's input port is compatible with single mode and step-index multimode FC/PC patch cables with cores up to Ø50 µm. Custom designs with other fiber
input receptacles are available upon request; please contact Tech Support for details. For the highest contrast, single mode patch cables are recommended. To
adapt a free-space input to the OSA201, please consider the procedures illustrated in the Free-Space Coupling tab above.
Part Number
OSA201
Description
Fourier Transform Optical Spectrum Analyzer, 350 - 1100 nm
Price
$24,250.00
Availability
Today
Hide Optical Spectrum Analyzer for 600 - 1700 nm
Optical Spectrum Analyzer for 600 - 1700 nm
600 - 1700 nm Wavelength Range Ideal for C-Band and L-Band Windows
FC/PC Fiber-Coupled Input
Noise Floor: -70 dBm/nm (Power Density Mode; See Design Tab for Details)
Includes Windows ® Laptop with Thorlabs' OSA Software Pre-Installed
Demo Units Available by Contacting Tech Support
Optimized for use in the 600 - 1700 nm spectral range, the OSA202 measures the optical power of both narrowband and broadband
sources as a function of wavelength. This spectral range includes the C-band (1530 - 1565 nm), L-band (1565 - 1625 nm), and other
Click to Enlarge
FC/PC Optical Fiber
Input
important telecom transmission windows. The maximum spectral resolution of 7.5 GHz (0.25 cm-1 ) is set by the maximum optical path length difference of ±4 cm, as
explained in the Design tab, while the high spectral accuracy of ±2 ppm (parts per million) is ensured by simultaneously measuring the interferogram of a stabilized
632.991 nm HeNe laser. For sources with linewidth < 10 GHz, enabling the Wavelength Meter mode provides 0.1 ppm resolution and ±1 ppm accuracy.
Fiber-Coupled Input
The OSA202's input port is compatible with single mode and step-index multimode FC/PC patch cables with cores up to Ø50 µm. Custom designs with other fiber
input receptacles are available upon request; please contact Tech Support for details. For the highest contrast, single mode patch cables are recommended. To
adapt a free-space input to the OSA202, please consider the procedures illustrated in the Free-Space Coupling tab above.
Part Number
OSA202
Description
Fourier Transform Optical Spectrum Analyzer, 600 - 1700 nm
Price
$24,250.00
Availability
Lead Time
Hide Optical Spectrum Analyzer for 1.0 - 2.6 µm
Optical Spectrum Analyzer for 1.0 - 2.6 µm
Wavelength Range Ideal for Molecular Absorption Bands and
Telecom Windows:
1.0 - 2.5 µm (10 000 - 4000 cm-1 ) in Low-Temperature
Mode
1.0 - 2.6 µm (10 000 - 3846 cm-1 ) in High-Temperature
Mode
Click to Enlarge
Free-Space Optical
Input Behind Door
Click to Enlarge
FC/PC Optical Fiber
Input Behind Door
Click for Details
Cage-Mounted Turning
Mirror Mounted on the
Free-Space Input
Click to Enlarge
Rear-Mounted Hose
Connections Around
Power Connector
Two Optical Input Ports:
FC/PC Fiber-Coupled Input
Free-Space Input with Red Alignment Beam and 4-40
Taps for 30 mm Cage Compatibility
TEC-Cooled Detector for Reduced Noise and Enhanced Level
Sensitivity
Noise Floor (Power Density Mode; See Design Tab for Details):
-70 dBm/nm in Low-Temperature Mode
-65 dBm/nm in High-Temperature Mode
Includes Windows ® Laptop with Thorlabs' OSA Software Pre-Installed
Built-In Hose Connections for Optional Purging
Demo Units Available by Contacting Tech Support
Optimized for use in the 1.0 - 2.6 µm spectral range, the OSA203B measures the optical power of both narrowband and broadband sources as a function of
wavelength. This spectral range includes molecular absorption bands for carbon monoxide, ammonia, and other compounds, as well as important telecom
transmission windows. The maximum spectral resolution of 7.5 GHz (0.25 cm-1 ) is set by the maximum optical path length difference of ±4 cm, as explained in the
Design tab, while the high spectral accuracy of ±2 ppm (parts per million) is ensured by simultaneously measuring the interferogram of a stabilized 632.991 nm
HeNe laser. For sources with linewidth < 10 GHz, enabling the Wavelength Meter mode provides 0.1 ppm resolution and ±1 ppm accuracy.
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Thorlabs.com - Optical Spectrum Analyzers
Cooled Detector with Temperature Control
The OSA203B has a thermoelectrically cooled (TEC) detector for reduced noise compared to our other OSA models. The detector's temperature can be toggled
between low-temperature and high-temperature (room-temperature) modes. In low-temperature mode, this optical spectrum analyzer achieves a very low noise
floor of -70 dBm/nm, with a wavelength range of 1.0 - 2.5 µm. In high-temperature mode, the sensitivity is -65 dBm/nm and the wavelength range is extended to
2.6 µm.
Fiber-Coupled and Free-Space Inputs
The OSA203B directly accepts fiber-coupled or free-space optical inputs. The fiber-coupled input is compatible with single mode and step-index multimode FC/PC
patch cables. For multimode patch cables made from standard silica glass, cores up to Ø50 µm are recommended; for multimode patch cables made from fluoride
glass, cores up to Ø100 µm are recommended. Single mode patch cables provide the highest contrast. The free-space input (illustrated at 2:54 in the video above)
accepts collimated input beams and has a Ø6 mm maximum beam size. When the free-space door is open, a red alignment beam is emitted that should be made
collinear and antiparallel to the unknown input. Four 4-40 taps around the free-space input provide compatibility with our 30 mm cage systems; use cage rods no
shorter than 1.5" to prevent attached cage components from clashing with the door.
If your application would benefit from detection extending out to 5.6 µm (1786 cm-1 ) or 12.0 µm (833 cm-1 ), please consider the OSA205 or OSA207 sold below.
Part Number
OSA203B
Description
Price
Fourier Transform Optical Spectrum Analyzer, 1.0 - 2.6 µm
$26,550.00
Availability
Today
Hide Optical Spectrum Analyzer for 1.0 - 5.6 µm
Optical Spectrum Analyzer for 1.0 - 5.6 µm
1.0 - 5.6 µm (10 000 - 1786 cm-1 ) Wavelength Range Ideal for
Fluoride Fiber Patch Cables Two Optical Input Ports:
FC/PC Fiber-Coupled Input
Free-Space Input with Red Alignment Beam and 4-40
Taps for 30 mm Cage Compatibility
Click to Enlarge
Free-Space Optical
Input Behind Door
Click to Enlarge
FC/PC Optical Fiber
Input Behind Door
Noise Floor: -40 dBm/nm (Power Density Mode; See Design Tab
for Details)
Includes Windows ® Laptop with Thorlabs' OSA Software PreInstalled
Built-In Hose Connections for Optional Purging
Demo Units Available by Contacting Tech Support
Click to Enlarge
Cage-Mounted
Polarizers in Front of
Free-Space Input
Click to Enlarge
Rear-Mounted Hose
Connections Around
Power Connector
Optimized for use in the 1.0 - 5.6 µm spectral range, the OSA205 measures the optical power of both narrowband and broadband
sources as a function of wavelength. This OSA is compatible with many of Thorlabs' quantum cascade and interband cascade
lasers, as well as single mode and multimode fluoride patch cables with cores up to Ø100 µm. Moreover, its broad wavelength range overlaps with that of many
FTIR spectrometers. The maximum spectral resolution of 7.5 GHz (0.25 cm-1 ) is set by the maximum optical path length difference of ±4 cm, as explained in the
Design tab, while the high spectral accuracy of ±2 ppm (parts per million) is ensured by simultaneously measuring the interferogram of a stabilized 632.991 nm
HeNe laser. For sources with linewidth < 10 GHz, enabling the Wavelength Meter mode provides 0.1 ppm resolution and ±1 ppm accuracy.
Fiber-Coupled and Free-Space Inputs
The OSA205 directly accepts fiber-coupled or free-space optical inputs. The fiber-coupled input is compatible with single mode and step-index multimode FC/PC
patch cables. For multimode patch cables made from standard silica glass, cores up to Ø50 µm are recommended; for multimode patch cables made from fluoride
glass, cores up to Ø100 µm are recommended. Single mode patch cables provide the highest contrast. The free-space input (illustrated at 2:54 in the video above)
accepts collimated input beams and has a Ø6 mm maximum beam size. When the free-space door is open, a red alignment beam is emitted that should be made
collinear and antiparallel to the unknown input. Four 4-40 taps around the free-space input provide compatibility with our 30 mm cage systems; use cage rods no
shorter than 1.5" to prevent attached cage components from clashing with the door.
If your application does not require detection in the 2.5 - 5.6 µm range (4000 - 1786 cm-1 ), please consider the OSA203B, sold above, which features a lower
minimum detectable power.
Part Number
OSA205
Description
Price
Fourier Transform Optical Spectrum Analyzer, 1.0 - 5.6 µm
$28,750.00
Availability
Today
Hide Optical Spectrum Analyzer for 3.3 - 8.0 µm
Optical Spectrum Analyzer for 3.3 - 8.0 µm
3.3 - 8.0 µm (3030 - 1250 cm-1 ) Wavelength Range Ideal for IR
Spectroscopy and Many QCLs
Two Optical Input Ports:
FC/PC Fiber-Coupled Input
Free-Space Input with Red Alignment Beam and 4-40
Taps for 30 mm Cage Compatibility
Click to Enlarge
Free-Space Optical
Input Behind Door
Noise Floor: -45 dBm/nm (Power Density Mode; See Design Tab
for Details)
Includes Windows ® Laptop with Thorlabs' OSA Software Pre-
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Click to Enlarge
FC/PC Optical Fiber
Input Behind Door
Thorlabs.com - Optical Spectrum Analyzers
Installed
Click to Enlarge
Cage-Mounted
Click to Enlarge
Polarizers in Front of
Demo Units Available by Contacting Tech Support
Rear-Mounted Hose
Free-Space Input
Connections Around
Optimized for use in the 3.3 - 8.0 µm spectral range, the OSA206 measures the optical power of both narrowband and broadband
Power Connector
sources as a function of wavelength. This OSA is compatible with the majority of our quantum cascade and interband cascade
lasers, as well as single mode and multimode fluoride patch cables with cores up to Ø100 µm. Moreover, its broad wavelength range overlaps with that of many
Built-In Hose Connections for Optional Purging
FTIR spectrometers, extending into the fingerprint region of the spectrum. The maximum spectral resolution of 7.5 GHz (0.25 cm -1 ) is set by the maximum optical
path length difference of ±4 cm, as explained in the Design tab, while the high spectral accuracy of ±2 ppm (parts per million) is ensured by simultaneously
measuring the interferogram of a stabilized 632.991 nm HeNe laser. For sources with linewidth < 10 GHz, enabling the Wavelength Meter mode provides 0.1 ppm
resolution and ±1 ppm accuracy.
Fiber-Coupled and Free-Space Inputs
The OSA206 directly accepts fiber-coupled or free-space optical inputs. The fiber-coupled input is compatible with single mode and step-index multimode FC/PC
fluoride patch cables with cores up to Ø100 µm. Single mode patch cables provide the highest contrast. The free-space input (illustrated at 2:54 in the video above)
accepts collimated input beams and has a Ø6 mm maximum beam size. When the free-space door is open, a red alignment beam is emitted that should be made
collinear and antiparallel to the unknown input. Four 4-40 taps around the free-space input provide compatibility with our 30 mm cage systems; use cage rods no
shorter than 1.5" to prevent attached cage components from clashing with the door.
If your application would benefit from a wider wavelength range and does not use broadband light sources, please consider the OSA207 sold above.
Part Number
OSA206
Description
Fourier Transform Optical Spectrum Analyzer, 3.3 - 8.0 µm
Price
$29,800.00
Availability
Lead Time
Hide Optical Spectrum Analyzer for 1.0 - 12.0 µm
Optical Spectrum Analyzer for 1.0 - 12.0 µm
1.0 - 12.0 µm (10 000 - 833 cm-1 ) Wavelength Range Ideal for
Quantum Cascade Lasers (QCLs)
Two Optical Input Ports:
FC/PC Fiber-Coupled Input
Free-Space Input with Red Alignment Beam and 4-40
Taps for 30 mm Cage Compatibility
Click to Enlarge
Free-Space Optical
Input Behind Door
Click to Enlarge
FC/PC Optical Fiber
Input Behind Door
Click for Details
Ø1/2" Off-Axis Parabolic
Mirror in CRM1P
Rotation Mount in Front
of Free-Space Input
Click to Enlarge
Rear-Mounted Hose
Connections Around
Power Connector
Noise Floor (Power Density Mode; See Design Tab for Details):
-30 dBm/nm for 1.0 - 2.0 µm
-40 dBm/nm for 2.0 - 12.0 µm
Includes Windows ® Laptop with Thorlabs' OSA Software PreInstalled
Built-In Hose Connections for Optional Purging
Demo Units Available by Contacting Tech Support
Optimized for use in the 1.0 - 12.0 µm spectral
range, the OSA207 measures optical power as a function of wavelength. This OSA is compatible with all of
Thorlabs' quantum cascade and interband cascade lasers, as well as single mode and multimode fluoride patch
cables with cores up to Ø100 µm. Moreover, its broad wavelength range overlaps with that of many FTIR
spectrometers, extending into the fingerprint region of the spectrum. The maximum spectral resolution of 7.5 GHz
(0.25 cm-1 ) is set by the maximum optical path length difference of ±4 cm, as explained in the Design tab, while the
high spectral accuracy of ±2 ppm (parts per million) is ensured by simultaneously measuring the interferogram of a
stabilized 632.991 nm HeNe laser. For sources with linewidth < 10 GHz, enabling the Wavelength Meter mode
Click to Enlarge
The OSA207's noise floor is too high to detect provides 0.1 ppm resolution and ±1 ppm accuracy.
broadband light sources like Thorlabs'
SLS202L (which was measured here with an Designed for Narrowband Sources
OSA205). We therefore primarily recommend Due to its broad wavelength responsivity, the OSA207's noise floor is higher than that of our other OSAs, which
the OSA207 for narrowband light sources.
achieve lower noise floors at the expense of having narrower wavelength ranges. Please see the Specs tab for
comparison graphs. This OSA will easily detect lasers and other narrowband sources, but many broadband sources will not have sufficient power spectral density to
be detected. Therefore, we recommend using Thorlabs' other OSAs if compatibility with broadband sources is required. The plot to the left compares the OSA207's
noise floor in Power Density mode to an ideal 1900 K black body and Thorlabs' SLS202L Stabilized Broadband Light Source.
Fiber-Coupled and Free-Space Inputs
The OSA207 directly accepts fiber-coupled or free-space optical inputs. The fiber-coupled input is compatible with single mode and step-index multimode FC/PC
fluoride patch cables with cores up to Ø100 µm. Single mode patch cables provide the highest contrast. The free-space input (illustrated at 2:54 in the video above)
accepts collimated input beams and has a Ø6 mm maximum beam size. When the free-space door is open, a red alignment beam is emitted that should be made
collinear and antiparallel to the unknown input. Four 4-40 taps around the free-space input provide compatibility with our 30 mm cage systems; use cage rods no
shorter than 1.5" to prevent attached cage components from clashing with the door.
Part Number
OSA207
Description
Fourier Transform Optical Spectrum Analyzer, 1.0 - 12.0 µm
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Price
$33,000.00
Availability
Lead Time
Thorlabs.com - Optical Spectrum Analyzers
Visit the Optical Spectrum Analyzers page for pricing and availability information:
https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=5276
https://www.thorlabs.com/newgrouppage9_pf.cfm?guide=10&category_id=220&objectgroup_id=5276[10/3/2016 11:54:08 AM]
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement