High-Power Fabry-Perot QCLs on D-Mounts

Webpage Features
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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)
• Compact D-Mount Design
  • QF4050D2: 12.0 mm x 6.0 mm x 2.1 mm (0.47" x 0.24" x 0.08")
  • QF4050D3 and QF4600D4: 12.0 mm x 7.5 mm x 2.1 mm (0.47" x 0.29" x 0.08")
• 4.05 µm (2469 cm^-1) or 4.6 µm (2174 cm^-1) Typical Center Wavelength
• High Typical CW Output Powers of 800 mW, 1200 mW, or 2500 mW
• Built-In Thermistor for Chip Temperature Measurements
• Used for MIR Illumination / Testing and Signal Simulation
• Custom Packages and Wavelengths from 3 to 12 µm Available by Contacting Tech Support

Designed for OEM customers, Thorlabs' High-Power D-Mount Fabry-Perot Quantum Cascade Lasers (QCLs) are among our most compact mid-IR lasers. Emitting at a 4.05 µm or 4.6 µm typical center wavelength, these lasers are mounted on a copper tungsten D-mount package that conserves space in situations where it is at a premium. Like our D-mount DFB laser, which feature a 4.5 mm cavity length, these D-mount FP lasers have an emission height of 2.6 mm, as measured from the bottom of the D-mount, but feature either a 6.0 mm or 7.5 mm cavity length. Each package is machined with two counterbored slots for mounting. The counterbored slots on the QF4050D2 are 1.5 mm long, and the counterbored slots on the QF4050D3 and QF4600D4 are 2 mm long. Compared to our FP lasers on C-mounts, these D-mount lasers provide higher optical output powers.

The drive voltage and current are supplied via two large gold contact pads, which are suitable for wire bonding or probe connections. Each QCL 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 25 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 these laser packages.

The output power of these Fabry-Perot QCLs is the sum over the full spectral bandwidth. Quantum cascade lasers are ideal for MIR illumination and testing as well as thermal signal simulation. 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 a high-reflection (HR) coated back facet and a partial-reflection (PR) coated front facet (see the Appearance tab for details). While these QCLs are specified for CW output, pulsed output is possible provided that the CW maximum 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 on performance, please contact Tech Support.

For industrial and academic research, Thorlabs manufactures both Distributed Feedback and Fabry-Perot Quantum Cascade Lasers that are mounted on two-tab C-mount packages. Using the LDMC20 C-Mount Laser Mount, these packages provide easier handling than D-mounts and can be interfaced to our SM1 lens tubes, 30 mm cage systems, and 60 mm cage systems.

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Maximum Output Power of Custom Fabry-Perot QCLs

FP QCLs at Custom Wavelengths

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 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.

Laser and Controller Compatibility

Controller Selection Guide

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 QF4050D2, QF4050D3, and QF4600D4 lasers, this value is 25 mW.

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.

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. 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.

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Two D-mount Fabry-Perot QCLs shown with a partial-reflection coating and solder on the front facet. The partial-reflectance coating is applied so that the laser meets specification, and the solder ensures the laser is mounted securely onto the D-mount package.

Appearance

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, all of 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.

Each D-mount QCL has a high-reflectance (HR) coated back facet and a partial-reflectance (PR) coated front facet. Finished units will show solder, which attaches the submounted laser onto the D-mount. The darker region on the D-mounts does not impair 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.