Clicking this icon opens a window that contains specifications and mechanical drawings.
Clicking this icon allows you to download our standard support documentation.
Clicking the words "Choose Item" opens a drop-down list containing all of the in-stock lasers around the desired center wavelength. The red icon next to the serial number then allows you to download L-I-V and spectral measurements for that serial-numbered device.
Compact D-Mount (12.0 mm × 4.5 mm × 2.8 mm) Fits into Small Assemblies
Center Wavelength in 7.00 - 8.00 µm Range (1429 - 1250 cm-1)
Output Can Be Tuned over 1 - 2 cm-1 Range
Typical CW Output Power of 100 mW
Built-In Thermistor for Chip Temperature Measurements
Used in Chemical Analysis, Sensing, and IR Countermeasures
Custom Packages and Wavelengths from 3 to 12 µm Available
Designed for OEM customers, Thorlabs' D-Mount Distributed Feedback Quantum Cascade Lasers (QCLs) are our most compact mid-IR lasers. Like our D-mount FP lasers, which feature a cavity length of either 6.0 mm or 7.5 mm, this D-mount DFB laser has an emission height of 2.6 mm, as measured from the bottom of the D-mount, but feature a 4.5 mm cavity length. The copper tungsten D-mount provides high thermal conductivity for heat dissipation and is machined with two 1.4 mm wide open counterbored slots for mounting, conserving space in situations where it is at a premium.
The drive voltage and current are supplied via two large gold contact pads, which are suitable for wire bonding or probe connections. Each laser is electrically isolated from its D-mount. A built-in thermistor provides real-time temperature measurements for the control electronics. Heat loads for these lasers can be up to 7.2 W, so they must be mounted in a thermally conductive housing to prevent heat buildup. Please see the Handling tab for more tips and information for handling this laser package.
Distributed Feedback QCLs emit at a well defined center wavelength and provide single spatial mode operation. By tuning the input current and operating temperature, the output frequency can be tuned over a narrow range of 1 - 2 cm-1. These lasers are ideal for chemical sensing and sample analysis applications. Before shipment, the output spectrum, optical power, and L-I-V curve are measured for each serial-numbered device by an automated test station. These measurements are available below and are also included on a data sheet with the laser.
Each D-mount QCL has an uncoated back facet and an uncoated or AR-coated front facet (see the Appearance tab for details). These QCLs are specified for CW output. While pulsed output is possible, this application prohibits current tuning, and performance is not guaranteed. These lasers do not have built-in monitor photodiodes and therefore cannot be operated in constant power mode.
Thorlabs manufactures custom and OEM quantum cascade lasers in high volumes. We maintain chip inventory from 3 µm to 12 µm at our Jessup, Maryland, laser manufacturing facility and can deliver DFB lasers with custom center wavelengths that are qualified to a user-defined wavelength precision.
More details are available on the Custom & OEM Lasers tab. To inquire about pricing and availability, please contact us. A semiconductor specialist will contact you within 24 hours or the next business day.
Dual Current / Temperature Controllers
Current and Temperature Controllers
Use the tables below to select a compatible controller for our MIR lasers. The first table lists the controllers with which a particular MIR laser is compatible, and the second table contains selected information on each controller. Complete information on each controller is available in its full web presentation. We particularly recommend our ITC4002QCL and ITC4005QCL controllers, which have high compliance voltages of 17 V and 20 V, respectively. Together, these drivers support the current and voltage requirements of our entire line of Mid-IR Lasers. To get L-I-V and spectral measurements of a specific, serial-numbered device, click "Choose Item" next to the part number below, then click on the Docs Icon next to the serial number of the device.
Provide External Temperature Regulation (e.g., Heat Sinks, Fans, and/or Water Cooling)
Use a Constant Current Source Specifically Designed for Lasers
Observe Static Avoidance Practices
Be Careful When Making Electrical Connections
Use Thermal Grease
Expose the Laser to Smoke, Dust, Oils, Adhesive Films, or Flux Fumes
Blow on the Laser
Drop the Laser Package
Use Solder with D-Mount Lasers
Handling D-Mount Lasers
Proper precautions must be taken when handling and using D-mount lasers. Otherwise, permanent damage to the device will occur. Members of our Technical Support staff are available to discuss possible operation issues.
Avoid Static Since these lasers are sensitive to electrostatic shock, they should always be handled using standard static avoidance practices.
Avoid Dust and Other Particulates Unlike TO can and butterfly packages, the laser chip of a D-mount laser is exposed to air; hence, there is no protection for the delicate laser chip. Contamination of the laser facets must be avoided. Do not blow on the laser or expose it to smoke, dust, oils, or adhesive films. The laser facet is particularly sensitive to dust accumulation. During standard operation, dust can burn onto this facet, which will lead to premature degradation of the laser. If operating a D-mount laser for long periods of time outside a cleanroom, it should be sealed in a container to prevent dust accumulation.
Use a Current Source Specifically Designed for Lasers These lasers should always be used with a high-quality constant current driver specifically designed for use with lasers, such as any current controller listed in the Drivers tab. Lab-grade power supplies will not provide the low current noise required for stable operation, nor will they prevent current spikes that result in immediate and permanent damage.
Thermally Regulate the Laser Temperature regulation is required to operate the laser for any amount of time. The temperature regulation apparatus should be rated to dissipate the maximum heat load that can be drawn by the laser. For our QD7500DM1 laser, this value is 7.2 W.
The bottom face of the D-mount package is machined flat to make proper thermal contact with a heat sink. Ideally, the heat sink will be actively regulated to ensure proper heat conduction. A Thermoelectric Cooler (TEC) is well suited for this task and can easily be incorporated into any standard PID controller.
A fan may serve to move the heat away from the TEC and prevent thermal runaway. However, the fan should not blow air on or at the laser itself. Water cooling methods may also be employed for temperature regulation. Do not use thermal grease with this package, as it can creep, eventually contaminating the laser facet. Pyrolytic graphite is an acceptable alternative to thermal grease for these packages.
Carefully Make Electrical Connections When making electrical connections, care must be taken. For D-mount lasers, solder should never be used; wire bonding or probe connections are the only recommended methods.
Minimize Physical Handling As any interaction with the package carries the risk of contamination and damage, any movement of the laser should be planned in advance and carefully carried out. It is important to avoid mechanical shocks. Dropping the laser package from any height can cause the unit to permanently fail.
Click to Enlarge D-Mount Laser with Uncoated Front Facet (Left) and AR-Coated Front Facet (Right)
In order to ensure that the finished lasers meet their target specifications, they are qualified by an automated test station before shipment. The test station measures the output spectrum, optical power, and L-I-V curve, which are included on a data sheet that ships with each serial-numbered laser. These measurements are also available below by clicking "Choose Item" and then clicking on the red Docs icon () that appears.
Because every laser is a unique device, certain units require the front facet to receive an anti-reflection (AR) coating to reach the specified output power. As a result, finished units will have varying appearances, as shown by the photo to the right. These cosmetic differences do not affect the performance of the laser when it is operated within its specified parameters. All shipped units have been burned in and have passed our rigorous optical performance, reliability, and environmental testing.
Custom & OEM Quantum Cascade and Interband Cascade Lasers
At our semiconductor manufacturing facility in Jessup, Maryland, we build a wide range of mid-IR lasers and gain chips. Our engineering team performs in-house epitaxial growth, wafer fabrication, and laser packaging. We maintain chip inventory from 3 µm to 12 µm, and our vertically integrated facilities are well equipped to fulfill unique requests.
High-Power Fabry-Perot QCLs For Fabry-Perot lasers, we can reach multi-watt output power on certain custom orders. The available power depends upon several factors, including the wavelength and the desired package.
DFB QCLs at Custom Wavelengths For distributed feedback (DFB) lasers, we can deliver a wide range of center wavelengths with user-defined wavelength precision. Our semiconductor specialists will take your application requirements into account when discussing the options with you.
The rows shaded green above denote single-frequency lasers.
7.00 - 8.00 µm Center Wavelength DFB QCLs, D-Mount
Tuning Range (Typ.)
Max Operating Currentb
Varies from 7.00 to 8.00 µm (1429 to 1250 cm-1)
100 mW (Typ.)
These lasers emit at a well defined wavelength that can be tuned over a narrow range. Each device has different optical characteristics. To get the spectrum and output power of a specific, serial-numbered device, click "Choose Item" below, then click on the Docs Icon next to the serial number. If you need a wavelength that is not listed below, please contact us.
Do not exceed the maximum optical power or maximum drive current, whichever occurs first.
Please note that the absolute maximum current is determined on a device-by-device basis. It is listed on the device's data sheet. To view, click "Choose Item" below, then click on the Docs Icon next to the serial number.