Chapter 5 - Mid-Infrared Semiconductor Lasers: A Review

Abstract

The mid-infrared (MIR) wavelength range of the electromagnetic spectrum offers a number of applications of growing importance such as photonic sensors for environment, industry or health monitoring, or defense and homeland security. This has driven over the last couple of decades the development of MIR semiconductor lasers at a rapid pace. This chapter aims at reviewing the progress in this field. Although II–VI or IV–VI compound semiconductors exhibit bandgaps in the MIR, other properties limit their use in semiconductor lasers. In contrast, the so-called antimonides, that is, III–V compound semiconductors based on GaSb, InAs, AlSb, InSb, and their alloys, appear to be well suited for developing a variety of lasers covering the whole MIR range. Laser diodes operating under continuous wave at room temperature have been demonstrated in the spectral range from 2 up to 3.5 μm. On the other hand, quantum cascade lasers emitting from 15 down to 2.6 μm have also been realized. Although further progress is possible for antimonide devices, they undoubtedly open the way to exploit the whole MIR wavelength range.