PRO8 DWDM DFB Laser Diode Modules

  • Complete Coverage of ITU Grid 
  • Wavelength Stability Better than 2 pm/24 h
  • Output Power Stability Better than 0.01 dB/24 h

PRO8 DWDM Laser Modules

PRO8000 Chassis
with 8 Modules

Easy to Read Display
No PC Required for Operation

Related Items

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PRO8 Series Modulesa
Laser Diode Current Controllers (Up to 8 A) PRO8000 Chassis with Modules
TEC Temperature Controllers (Up to 64 W)
Combination Laser Diode Current (Up to 1 A) &
TEC Temperature Controllers (Up to 16 W)
DWDM DFB Laser Modulesb
Optical Switches
Photocurrent Measurement Modules
  • Our PRO8 Series Chassis can accommodate multiple PRO8 Series Modules, allowing for a customized telecom solution.
  • Please contact Tech Support for availability of desired wavelength.


  • Center Wavelengths on 100 GHz ITU Grid
  • Wavelengths in C and L Bands
  • Output Power: 20 mW
  • Wavelength Stability:< 2 pm / 24 hrs
  • Extremely Stable Output Power < 0.01dB / 24 hrs
  • Precise Wavelength Tuning: ± 0.85 nm
  • Direct Display of Wavelength During Tuning
  • Precise Power Attenuation: >6 dB (10 dB Typ.)
  • Variable Coherence Control, Linewidths Adjustable up to 1 GHz
  • Instrument Drivers for LabVIEW™ & LabWindows/CVI™
  • FC/APC Connector

These modules are distributed feedback (DFB) laser sources designed for use with our PRO8 Series Chassis. These sources have precise tunability as well as long-term wavelength and power stability. Provided with adjustable coherence control, these laser modules are ideally suited for all dense wavelength division multiplexing (DWDM) applications such as test systems for fiber optic DWDM components, EDFA manufacturing, and multi-laser optical sources for DWDM transmission experiments. The PRO8 Chassis can be ordered with these modules preinstalled; contact Tech Support prior to placing your order.

Stability, Accuracy, and Dependability
This DWDM laser platform is the ideal choice for demanding DWDM test and measurement applications with laser linewidths of less than 10 MHz, center wavelength stability of better than 0.002 nm per 24 hours, and wavelength accuracy of better than ±0.025 nm. We use only telecom-rated, butterfly packaged DFB lasers with integrated TEC elements, optical isolators, and low back-reflection fiber pigtails. When combined with our sophisticated drive circuits, the result is an extremely stable, low-noise laser source that exhibits optical power stability better than 0.005 dB per 15 minutes and a relative intensity noise RIN figure of typ. -145 dB/Hz. All Thorlabs' instruments are backed by an extensive two-year warranty on materials and workmanship.

Extensive Inventories
Thorlabs' DWDM sources cover the ITU-T DWDM grid containing 100 wavelengths (100 GHz channels) spanning the C and L Bands. Many of these lasers ship directly from stock. Wavelengths on the 50 GHz and 25GHz grid are available on request. Thorlabs also offers the service of incorporating user-supplied lasers into our modules. Please contact Thorlabs for details. Our laser sources are supplied with PM fiber and a non-orientated FC/APC connector. For details on customized options, please contact Thorlabs.

Coherence Control, Internal Modulation
For high-precision power measurements, the narrow linewidth of a DFB laser can lead to interference effects caused by reflections from the multiple surfaces that are present in most optical systems. These multiple reflections, while extremely small, can accumulate due to the long coherence length of the laser light. Brillouin scattering is another effect that can lead to significant errors when making optical power measurements in fiber-based systems.

The magnitude of these effects can be significantly reduced by increasing the linewidths of the source. Therefore, all the DWDM-series laser sources provide an adjustable coherence length control. Here a small signal modulation on the laser current is used to broaden the DFB laser linewidth from a few MHz up to more than 1GHz. The PRO8 provides continuous adjustment of the linewidth over this entire range. An internal broadband noise source or an internal, freely running, sine wave/square wave generator is used to modulate the laser current. The modulation frequency range of the function generator is 20 Hz to 50 kHz with up to 100% modulation depths. Using these features, an ideal non-discrete Gaussian-shaped distribution or a discrete spectral distribution is generated.

External Digital Modulation, DC to 10 kHz
All laser modules within a chassis can be modulated synchronously by an external TTL signal. The modulation bandwidth ranges from DC to 10 kHz. The modulation signal input is on the back panel of the chassis and operates simultaneously on all laser modules of the chassis.

External Analog LF Modulation, DC to 50 kHz (Optional)
For applications where a precise LF modulation up to 50 kHz is required, the DWDM modules are available with an LF modulation option. With this option, the output power can be modulated via an optional SMA input. The laser remains fully protected due to a precise limit circuit located inside the module. To order the source with the external analog LF modulation option, please contact Tech Support.

Precision Wavelength Tuning
The wavelength is displayed with a resolution of 0.001 nm on the PRO8 front panel or can be read through the IEEE-488 interface with a resolution of 0.001 nm. By precisely controlling the temperature of the laser chip, the emitted wavelength can be tuned over a range of ±0.85 nm (approximately ±100 GHz). This range allows the central wavelength of the source to be shifted from one transmission channel to either of the adjacent channels for dense WDM systems with 100 GHz channel spacing or tuning over up to 8 channels for systems with 25 GHz channel spacing. This feature is useful for simulating crosstalk between channels. It can also be used to measure the profile of narrow band DWDM filters. Manual polarization controllers can be supplied as accessories for laser modules. They can be used to adapt the state of polarization in the fiber to polarizationdependant external modulators.

For further information, please contact Tech Support.

Technical Data PRO8 DWDM Laser Modules
Options 100 Wavelengths within 100 GHz ITU Grid in C and L-Banda
Tuning Range ±0.85 nm
Accuracy ±0.025 nm, Typ. <±0.01 nm
Stability (Typ.) <0.002 nm over 24 hrs
Resolution 1 pm
Laser Linewidth <10 MHz
Output Power
Optical Power 20 mW
Accuracy (Abs. / Rel.) 0.6 dB / 0.4 dB
Stability (Coherence Control Active) <0.002 dB over 15 s,
<0.005 dB over 15 minutes,
<0.01 dB over 24 hours
Attenuation Range >6 dB; 10 dB Typ. (Continuously Variable)
Resolution 0.01 dB
Side Mode Suppression Ratio (SMSR) >40 dB Typ. (>36 dB Min.) at Max. Power
Relative Intensity Noise (RIN) -145 dB/Hz Typ.
Optical Isolation >35 dB
Coherence Control (Standard Feature, All Models)
Linewidth Up to 1 GHz (Adjustable)
Shape Noise, Sine & Square (Triangle Upon Request)
Bandwidth (Noise) ~ 0.2 to 5 kHz
Frequency (Sine, Square) 0.02 to up to 50 kHz
Modulation Depth (Noise) 0.1 to 10 %
Modulation Depth (Sine, Square) 0.1 to 100 %
ON/OFF Modulation 0.02 to up to 50 kHz
Synchronous TTL 0 to 10 kHz (All Lasers Within Mainframe Simultaneously via Common BNC Input)
Analog LF Modulation DC to 50 kHz (Option, via SMA Input at the Module)
General Data
Optical Output (Standard) FC/APCb
Fiber PMFc
Operating Temperature 0 to +35 °C (Non-Condensing)
Storing Temperature -40 to +60 °C
Warm-Up Time for Rated Accuracy 15 min
Module Width 1 PRO8 Slot
Weight <0.5 kg
Laser Safety Class 1M
  • Subject to DFB laser diode availability, 25 GHz and 50 GHz grid on request
  • Other connector styles (SC, E2000...) and non-angled (PC) ferrule on request
  • Connector key aligned to slow axis upon request
    (All technical data is valid at 23 ± 5°C and 45 ±15% rel. humidity)

The following parts are included together with each of our PRO8 WDM Sources:

  • WDM8000 Laser Source Module DWDM (WDM8-X-XXX-20-NM)
  • Operating Manual

Posted Comments:
user  (posted 2024-05-01 10:49:12.507)
Is the output connector wide key or narrow key ? Although Thorlabs only sell narrow key patchcords, some of your components are wide key...
hchow  (posted 2024-05-02 07:41:16.0)
Dear User, thank you for your feedback. The FC/APC output connector on the DFB Laser Diode Modules are of the narrow key type.
Robert Carlson  (posted 2023-08-19 09:33:29.05)
Please confirm whether this will work with a Pro8 DFB laser module: 50 kHz sinewave input from signal generator, for laser output 50 kHz sinewave with 90% modulation depth. Thanks!
hchow  (posted 2023-08-24 03:13:59.0)
Dear Mr. Carlson, yes, the PRO8 DWDM DFB Laser Diode Module can indeed be connected to a signal generator to generate laser output at 50 kHz sine waves with a 90% modulation depth.
DoHeung Je  (posted 2021-04-26 06:03:35.253)
Hello! I'm using your PRO8 DWDM8 Laser module. Its connector key is 45 degrees clockwise. PMF whose connector key is slow axis direction is connected with the output of the module. Is this connection right? How can I find the polarization axis of the output connector of the module?
MKiess  (posted 2021-05-03 10:37:36.0)
Dear DoHeung Je, thank you very much for your inquiry. On the newer laser models, the connector key is aligned to the slow axis. On older models this could be arbitrary. To measure the polarization at the output you could use for example a PAX1000IR2. I have contacted you directly to discuss further measurement methods.
parpar  (posted 2017-07-04 18:49:01.31)
The product is very useful, we are looking for additional laser sources/modules at 1200-1500nm wavelengths... can you offer something in this range? Thanks
swick  (posted 2017-07-10 03:41:40.0)
This is a response from Sebastian at Thorlabs. Thank you for the inquiry. At the time we have no plans to offer DWDM sources for 1200-1500nm. However, we will internally evaluate this suggestion.
mrandall  (posted 2016-07-04 12:52:14.23)
Do you do a fixed price repair of these modules? I have several which no longer meet wavelength accuracy.
shallwig  (posted 2016-07-05 03:13:40.0)
This is a response from Stefan at Thorlabs. Thank you for your inquiry, we have to inspect the modules before we can estimate a price for repair. I have contacted you directly for setting up an RMA.




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Recalibration Service for WDM Modules for PRO8 Series Chassis

Thorlabs offers a calibration service for the WDM Series Laser Diode Modules for our PRO8 Series Chassis. To ensure accurate measurements, we recommend recalibrating the devices every 24 months.

Requesting a Calibration
Thorlabs provides two options for requesting a calibration:

  1. Complete the Returns Material Authorization (RMA) form. When completing the RMA form, please enter your name, contact information, the Part #, and the Serial # of the item being returned for calibration; in the Reason for Return field, select "I would like an item to be calibrated." All other fields are optional. Once the form has been submitted, a member of our RMA team will reach out to provide an RMA Number, return instructions, and to verify billing and payment information.
  2. Enter the Part # and Serial # of the item that requires recalbration below and then Add to Cart. A member of our RMA team will reach out to coordinate return of the item for calibration. Should you have other items in your cart, note that the calibration request will be split off from your order for RMA processing.

Please Note: To ensure your item being returned for calibration is routed appropriately once it arrives at our facility, please do not ship it prior to being provided an RMA Number and return instructions by a member of our team.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
CAL-WDM8 Support Documentation
CAL-WDM8Recalibration Service for the WDM Series Modules for PRO8 Chassis
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