Room-temperature quantum-cascade lasers generate 200 mW at 5.2 microns

July 1, 1996
Modifying the design of a vertical-transition quantum-cascade laser has enabled Jerome Faist and coworkers at Lucent Technologies, Bell Laboratories (Murray Hill, NJ) to develo¥devices capable of pulsed-mode, room-temperature operation, thus demonstrating the first uncooled mid-infrared-emitting laser. In quantum-cascade lasers, electrons tumble between upper and lower energy levels in a quantum well, emitting photons in the process; the thickness of the quantum-well layer determines emissio

Room-temperature quantum-cascade lasers generate 200 mW at 5.2 microns

Modifying the design of a vertical-transition quantum-cascade laser has enabled Jerome Faist and coworkers at Lucent Technologies, Bell Laboratories (Murray Hill, NJ) to develo¥devices capable of pulsed-mode, room-temperature operation, thus demonstrating the first uncooled mid-infrared-emitting laser. In quantum-cascade lasers, electrons tumble between upper and lower energy levels in a quantum well, emitting photons in the process; the thickness of the quantum-well layer determines emission wavelength. The new devices, described in paper CPD9-2 at CLEO `96, consist of indium gallium arsenide/aluminum indium arsenide (InGaAs/AlInAs) heterostructures grown on indium phosphide (InP) substrates. The In¥cladding offers a lower thermal resistance than the AlInAs cladding used on previous designs, allowing increased operating temperature (see Laser Focus World, June 1994, p. 15 ). To increase gain, the design features a three-well active region, low n-type doping, and a "funnel injector"--a narrowed miniband to guide electrons to the upper state of the next period.

At 300 K, the 5.2-µm devices generated peak powers of 200 mW; at 320 K, output power was above 100 mW. Corresponding average powers ranged from 5 to 10 mW. All results were obtained in pulsed mode, with pulse durations of 50 ns at 670 kHz. In continuous wave mode, the devices still require cooling and produced average powers of 2 mW at 140 K. The researchers have also produced room-temperature devices operating at 8.5 µm with peak powers of around 13 mW.

Sponsored Recommendations

Brain Computer Interface (BCI) electrode manufacturing

Jan. 31, 2025
Learn how an industry-leading Brain Computer Interface Electrode (BCI) manufacturer used precision laser micromachining to produce high-density neural microelectrode arrays.

Electro-Optic Sensor and System Performance Verification with Motion Systems

Jan. 31, 2025
To learn how to use motion control equipment for electro-optic sensor testing, click here to read our whitepaper!

How nanopositioning helped achieve fusion ignition

Jan. 31, 2025
In December 2022, the Lawrence Livermore National Laboratory's National Ignition Facility (NIF) achieved fusion ignition. Learn how Aerotech nanopositioning contributed to this...

Nanometer Scale Industrial Automation for Optical Device Manufacturing

Jan. 31, 2025
In optical device manufacturing, choosing automation technologies at the R&D level that are also suitable for production environments is critical to bringing new devices to market...

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!