- Five Models Optimized for Different Spectral Ranges
OSA202C: 600 - 1700 nm
OSA203C: 1.0 - 2.6 µm (10 000 - 3846 cm-1)
OSA205C: 1.0 - 5.6 µm (10 000 - 1786 cm-1)
OSA207C: 1.0 - 12.0 µm (10 000 - 833 cm-1)
- Two Optical Input Ports
- FC/PC Fiber-Coupled Input
- Free-Space Input with Four 4-40 Taps for 30 mm Cage System Compatibility
- Built-In Hose Connections for Optional Purging
- Includes Windows® Laptop and Items Shown in Shipping List Tab
Thorlabs' OSAs measure the optical power of both narrowband and broadband sources as a function of wavelength. 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 632.9918 nm HeNe laser. For sources with linewidth <10 GHz, the Wavelength Meter mode provides center wavelength measurements with 0.1 ppm resolution and ±1 ppm accuracy.
FC/PC Fiber Receptacle Behind Door (OSA202C Shown)
Free-Space Optical Input for Ø6 mm Beam Behind Door (OSA202C Shown)
Rear-Mounted Hose Connections for Purging on the OSA20xC Instruments
Ø1/2" Off-Axis Parabolic Mirror in CRM1PT Rotation Mount in Front of Free-Space Input
Fiber-Coupled and Free-Space Inputs
All of our OSAs directly accept fiber-coupled or free-space optical inputs. The fiber-coupled input is compatible with single mode and multimode FC/PC patch cables. For multimode patch cables made from standard silica glass, cores up to Ø50 µm and NA up to 0.22 are recommended; for those made from fluoride glass, cores up to Ø100 µm and NA up to 0.26 are recommended. Single mode patch cables provide the highest contrast. OSAs with other fiber input receptacles are available by contacting Tech Support.
The free-space input aperture accepts collimated input beams up to a maximum beam size of Ø6 mm. To align the input light with respect to the OSA's internal interferometer, a red, Class 1 alignment beam, which is activated by a rotating switch, is emitted from the aperture. (See 2:47 in the video above for a demonstration.) The input beam should be made collinear to the alignment beam for the OSA to provide optimal measurement accuracy. Four 4-40 taps around the input aperture enable compatibility with our 30 mm cage system; use cage rods no shorter than 1.5" to prevent attached cage components from clashing with the door. For more information on free-space coupling, please see the Free-Space Coupling tab.
Hose Inlets for Optional Purging
To reduce the presence of water absorption lines in the measured spectrum, our OSAs offer two 1/4" inner diameter quick-connect hose connections on the back panel, through which the interferometer can be purged with dry air. Thorlabs' Pure Air Circulator Unit is ideal for this task. Purging the OSA is not generally necessary, since none of the optics are made from hygroscopic materials, but can be useful for applications such as gas detection and identification where the presence of trace gases in the housing may affect the measurement. An example setup that uses the OSA203C instrument is described in the Gas Spectroscopy tab.
Software
Each OSA20xC instrument includes a Windows® laptop with our OSA software suite version 2.90 pre-installed and a USB 2.0 cable. This software has a graphical user interface (GUI) that includes a variety of measurement and analysis tools; please see the Software tab for a detailed overview of the software capabilities. To easily interface with the OSAs, an extensive set of drivers are also available for LabVIEW®, C, C++, and C#.
| Specification | Notes | Value |
| Spectral Resolution | - | 7.5 GHz (0.25 cm-1) |
| Spectral Accuracy (a) | ±2 ppm (b) | |
| Spectral Precisionc | 1 ppm | |
| Wavelength Meter Resolution |
Wavelength Meter Mode (Linewidth <10 GHz) See Section 4.6 |
0.1 ppm |
| Wavelength Meter Display Resolution (d) | 9 Decimals | |
| Wavelength Meter Accuracy (a) | ±1 ppm | |
| Wavelength Meter Precision (e) | 0.2 ppm | |
| Input Power (Max) | CW Source | 10 mW (10 dBm) |
| Input Damage Threshold (f) | - | 20 mW (13 dBm) |
| Power Level Accuracy (g) | - | ±1 dB |
| Optical Rejection Ratio | See Section 4.13 | 30 dB |
| Input Fiber Compatibility | - |
FC/PC Connectorsh All Single Mode Patch Cables, Including Fluoride SM Patch Cables Silica Multimode Patch Cables with ≤Ø50 µm Core and NA ≤ 0.22 Fluoride Multimode Patch Cables with ≤Ø100 µm Core and NA ≤ 0.26 |
| Free-Space Input | - |
Accepts Collimated Beams up to Ø6 mm Red Alignment Laser Beam Four 4-40 Taps for 30 mm Cage Systems |
| Dimensions | - |
320 mm x 149 mm x 475 mm 18.7") |
a. After a 45-minute warm-up, for a single mode FC/PC-terminated patch cable at an operating temperature of 20 - 30 ºC.
b. Specified in parts per million. For instance, if the wavelength being measured is 1 μm, the spectral accuracy will be
±2 pm. (±2 pm of accuracy for every 1,000,000 pm, or 1 μm, of wavelength.)
c. Spectral Precision is the repeatability with which a spectral feature can be measured using the peak search tool.
d. Can be set from 0-9 decimals and have an auto option that estimates the relevant number of decimals.
e. Using the same input single mode fiber for all measurements.
f. Limited by the damage threshold of the internal components
g. 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.) The specified wavelength range is 400 - 1000 nm for OSA201C, 600 - 1600 nm for OSA202C, 1.0 -
2.4 μm for OSA203C, 1.3 - 5.0 μm for OSA205C, and 2.0 - 11.0 μm for OSA207C. Each specification is valid for a
single mode FC/PC-terminated patch cable, as well as for a collimated free-space beam with diameter < 3 mm and
divergence < 3 mrad, assuming the included protective window is installed in the free-space aperture.
h. Connectors for other fiber input receptacles are available upon request.