Carrier-rebalanced interband cascade lasers require very low input powers

Abstract

Abstract : The recent availability of midwave-IR semiconductor lasers capable of emitting narrow spectral lines at ambient or thermoelectric-cooler temperatures (above -20 deg C) has spawned the development of a new generation of chemical sensing systems designed to exploit the prevalence of strong mid-IR spectroscopic signatures. Although the required laser output powers tend to be rather modest (less than or equal 1mW), minimizing the drive power can be critical because the most attractive systems will be quite compact and often powered by batteries. Several distinct classes of mid-IR semiconductor lasers are currently being developed. The antimonide interband cascade laser (ICL) combines the interband active transitions of a conventional diode laser with the multiple cascaded stages of a quantum cascade laser (QCL). Previous ICLs demonstrated spectral coverage of at least 2.9 4.2 microns, and continuous wave operation up to 72 deg. C. Redesigned ICLs incorporating carrier rebalancing have, by several key figures of merit, displayed record-setting performance compared to all previous mid-IR semiconductor lasers.