GaSb-based lasers with two-dimensional photonic crystal mirrors

We present the realization of two-dimensional (2D) photonic crystals (PhCs) on the GaSb material system. An electron cyclotron resonance reactive ion etch process using Cl(2)/Ar allows the fabrication of PhCs covering air fill factors of f = 20%-50%, lattice periods of a = 400-500 nm and aspect ratios of 5:1. Quality and reflectivity of these structures are evaluated by incorporating the PhCs as high reflective back mirrors in GaSb-based ridge waveguide lasers with cavity lengths between 200 and 1100 µm with the front facet as cleaved. The shortest devices show remarkable threshold currents below 12 mA and efficiencies of 0.23 W A(-1), yielding a maximum output power of almost 19 mW, proving the applicability of the chosen approach to numerous further concepts based on 2D PhCs on the GaSb material system.