Interband cascade lasers on GaSb substrates emitting beyond 5.6pm

Abstract

Since the first theoretical prediction by Yang [1] and the first experimental realization [2] interband cascade lasers (ICL) became more and more established for gas sensing applications. The ICL combines the cascading of several active stages known from the quantum cascade laser (QCL) and the interband transition of the diode lasers (DL) enabled by the semimetallic interface between InAs and GaSb where electrons can efficiently tunnel from the valenceband to the conduction band. The optimal workspace of ICLs is between 3–5μm where their low power consumption is unrivaled compared with QCLs [3] and DLs [4]. Since important gases like e.g. nitrogen oxides have strong absorption lines beyond 6 μm, the extension beyond the actual long wavelength record on GaSb substrates [5] is promising for industrial applications.