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)
• Center Wavelength of 3.85, 4.04, or 4.65 µm
• Horizontal, Collimated, Vertically Polarized Output
• High Heat Load Package Simplifies Thermal Management and System Integration
• Custom Wavelengths and Mounts Also Available (Contact Tech Support for Details)

Thorlabs' Fabry-Perot Quantum Cascade Lasers (QCLs) exhibit broadband emission spanning 50 cm^-1. The laser's specified output power is the sum over the full spectral bandwidth. Since these QCLs have broadband emission, they are well suited for medical imaging, MIR illumination, and microscopy applications. The output spectrum, L-I-V curve, and beam propagation data of each serial-numbered device, measured by an automated test station before shipment, are available below and are also included on a data sheet that ships with the device.

Our QCLs emit a vertically polarized, collimated beam. At the output, a wedged zinc sulfide window AR-coated for 3.5 - 6 µm prevents back reflections from returning to the laser chip, but also causes the beam to exit the mount at a 2.0 ± 0.6° angle. A thermoelectric cooler and a thermistor are integrated into each laser for temperature control. The laser package is sealed, although the seal is not hermetic.

Although these lasers are specified for CW output, they are compatible with pulsed applications provided that the CW max operating current is not exceeded. These lasers do not have built-in monitor photodiodes and therefore cannot be operated in constant power mode. For more information or for custom options, please contact Tech Support.

Mounts and Drivers
HHL lasers are compatible with any HHL mount, although cables for HHL packages are typically not rated for the 6 A maximum current of the internal thermoelectric cooler. 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 70 W (see the Handling tab for additional information).

The QCLs on this page have operating voltages up to 15 V. We recommend using drivers such as our ITC4002QCL or ITC4005QCL Dual Current / Temperature Controller, which are rated to support this high operating voltage. See the Drivers tab for more information.

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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 a broad chip inventory 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
When designing your own mounting solution, note that due to these lasers' heat loads, we recommend that they be secured in a thermally conductive housing with sufficient cooling capacity, either active or passive, to prevent heat buildup. The total heat loads for the Fabry-Perot QCL HHL package can be up to 70 W, although a typical heat load from a Fabry-Perot QCL itself is around 20 W.

Laser and Controller Compatibility

• Please note that Thorlabs does not offer cables that connect high heat load lasers to our controllers, and that third-party cables for these packages are typically not rated for the 6 A maximum current of the internal thermoelectric cooler. Custom cables will be required.

Controller Selection Guide

Handling High Heat Load Lasers

Proper precautions must be taken when handling and using high heat load 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
Contamination of the window must be avoided. Do not blow on the window or expose it to smoke, dust, oils, or adhesive films. The window is particularly sensitive to dust accumulation. During standard operation, dust can burn onto it, which will lead to premature degradation of the laser performance. If operating a high heat load 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. 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 high heat load DFB QCLs and ICLs, this value is 38 W. For our high heat load Fabry-Perot QCLs, this value is 70 W.

The bottom face of the high heat load package is machined flat to make proper thermal contact with a heat sink. Ideally, the heat sink will be actively temperature regulated to ensure proper heat conduction. A fan may serve to move the heat away from the package and prevent thermal runaway. However, the fan should not blow air on or at the laser itself. Thermal grease, pyrolytic graphite, and water cooling methods may also be employed for temperature regulation.

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.

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 6 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.

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.

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Some of Our Available Packages

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Wire Bonding a Quantum Cascade Laser on a C-Mount

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 graphs below and photos to the right illustrate some of our custom capabilities. Please visit our semiconductor manufacturing capabilities presentation to learn more.

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Available Wavelengths for Custom QCLs and ICLs

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Maximum Output Power of Custom Fabry-Perot QCLs

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Electroluminescence Spectra of Available Gain Chip Material