Webpage Features
	Clicking this icon opens a window that contains specifications and mechanical drawings.
	Clicking this icon allows you to download our standard support documentation.
Choose Item	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.

Features

• Broadband Fabry-Perot Quantum Cascade Lasers (QCLs)
• Standard Ø9 mm TO Can Package with ZnSe or Sapphire Window
• Up to 1000 mW CW Output Power
• 3.85 µm, 4.05 µm, or 4.60 µm Center Wavelengths (2597 cm^-1, 2469 cm^-1, or 2174 cm^-1 Wavenumbers)
• Custom Wavelengths and Packages Also Available (Contact Tech Support for Details)

Thorlabs' TO-can-packaged Fabry-Perot Quantum Cascade Lasers provide the power and broadband mid-IR emission of a Fabry-Perot QCL in a convenient Ø9 mm TO-can package. The broadband emission of each laser makes them well suited for medical imaging, illumination, and thermal signal simulation. The Ø9 mm TO-can package incorporates an additional copper disk for added heat dissipation. The additional material makes this TO-can thicker than standard Ø9 mm packages, but the lasers are still compatible with all Ø9 mm laser mounts. An AR-coated ZnSe or AR-coated sapphire window, depending on the product, protects the device from dust and debris.

The output power of each Fabry-Perot QCL is the sum over the full spectral bandwidth. 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. After clicking "Choose Item" below, a list will appear that contains the dominant wavelength, output power, and operating current of each in-stock unit. Clicking on the red Docs Icon next to the serial number provides access to a PDF with serial-number-specific L-I-V and spectral characteristics.

While each QCL is specified for CW output, pulsed output is possible. These lasers do not have a built-in monitor photodiode and therefore cannot be operated in constant power mode.

Mounts, Drivers, and Temperature Control
The LDM90 Laser Mount along with the ITC4002QCL or ITC4005QCL Dual Current / Temperature Controller includes all the necessary components to mount, drive, and thermally regulate these lasers up to the 8 W cooling capacity of the LDM90. When run at full power, some QCLs may exceed the cooling capacity of the LDM90. Therefore, care must be taken that the product of the operating current and forward voltage does not exceed 8 W. The individual spec sheet of each quantum cascade laser will list typical values for operating current and forward voltage.

If designing your own mounting solution, note that due to these lasers' heat loads, we recommend that they be mounted in a thermally conductive housing to prevent heat buildup. Heat loads for Fabry-Perot QCLs can be up to 18 W (see the Handling tab for additional information).

Click to Enlarge
Maximum Output Power of Custom Fabry-Perot QCLs

High-Power OEM & Custom Lasers

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 reach multi-watt output on certain custom orders.

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.

Current and Temperature Controllers

Use the tables below to select a compatible controller for for our MIR lasers. The first table lists the controllers with which the 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.

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.

Laser Mount Compatibility
Thorlabs' LDM90 Laser Mount is fully compatible with the ITC4002QCL and ITC4005QCL controllers; however, the mount itself has a limited heat load of 8 W, meaning some QCLs cannot be driven at full power in this mount. If designing your own mounting solution, note that due to these lasers' heat loads, we recommend that they be secured in a thermally conductive housing to prevent heat buildup. Heat loads for QCLs can be up to 12 W.

Laser and Controller Compatibility

Controller Selection Guide

• Thorlabs does not currently offer cables that connect the LDMC20 mount to this controller. Custom cables will be required.

Handling TO Can, Two-Tab C-Mount, D-Mount, and High Heat Load Lasers

Proper precautions must be taken when handling and using TO Can, two-tab C-mount, D-mount, or high heat load (HHL) 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 C-mount or 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 C-mount or D-mount laser for long periods of time outside a cleanroom, it should be sealed in a container to prevent dust accumulation.

HHL lasers and TO cans are sealed (although the seal is not hermetic), so the laser chip will not be exposed to air. However, similar dust avoidance precautions should be followed for the window on these packages, since the windows are exposed to the atmosphere.

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 two-tab C-mount or TO can quantum cascade lasers, this value can be up to 18 W. The LDMC20 C-Mount Laser Mount, which is compatible with our two-tab C-mount package, is rated for >20 W of heat dissipation. The LDM90 Ø9 mm TO Can Laser Mount is only rated for 8 W of heat dissipation, so some quantum cascade lasers cannot be operated at full power. Our DFB D-mount laser's maximum heat load is 7.2 W, our FP D-mount lasers' maximum heat load is 25 W, and our HHL QCLs have a maximum heat load of 38 W.

The back face of the C-mount package and the bottom face of the D-mount or high heat load 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. The HHL package incorporates a suitable TEC.

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. Although thermal grease is acceptable for TO can and HHL lasers, it should not be used with two-tab C-mount or D-mount lasers, since it can creep, eventually contaminating the laser facet. Pyrolytic graphite is an acceptable alternative to thermal grease for these cases. Solder can also be used to thermally regulate two-tab C-mount lasers, although controlling the thermal resistance at the interface is important for best results. Solder is not recommended for thermal regulation of D-mount or HHL lasers.

For assistance in picking a suitable temperature controller for your application, please contact Tech Support.

Carefully Make Electrical Connections
When making electrical connections, care must be taken. The flux fumes created by soldering can cause laser damage, so care must be taken to avoid this.

Solder can be avoided entirely for two-tab C-mount and TO can lasers by using the LDMC20 or LDM90 laser mounts, respectively. If soldering to the tabs on a two-tab C-mount, solder with the C-mount already attached to a heat sink to avoid unnecessary heating of the laser chip. We do not recommend soldering lasers in TO can packages.

Although soldering to the leads of our HHL lasers is possible, we generally recommend using cables specifically designed for HHL packages. Please note that third-party cables for high heat load packages are typically not rated for the 4.5 A maximum current of the internal thermoelectric cooler. If soldering to the leads on an HHL package, the maximum soldering temperature and time are 250 °C and 10 seconds, respectively.

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.