GaSb-based lasers with two-dimensional photonic crystal mirrors

Abstract

We present the realization of two-dimensional (2D) photonic crystals (PhCs) on the GaSbmaterial system. An electron cyclotron resonance reactive ion etch process usingCl2/Ar allows the fabrication of PhCs covering air fill factors off = 20%–50%, latticeperiods of a = 400–500 nm and aspect ratios of 5:1. Quality and reflectivity of these structuresare evaluated by incorporating the PhCs as high reflective back mirrors inGaSb-based ridge waveguide lasers with cavity lengths between 200 and1100 µm with thefront facet as cleaved. The shortest devices show remarkable threshold currents below 12 mA and efficienciesof 0.23 W A−1, yielding a maximum output power of almost 19 mW, proving the applicability of thechosen approach to numerous further concepts based on 2D PhCs on the GaSb materialsystem.