Photonic Crystal Surface Emitting Diode Lasers with lambda near 2 mu m

Epitaxially regrown electrically pumped photonic crystal surface emitting lasers (PCSELs) operating near 2 mu m were designed and fabricated within a III-V-Sb material system. A high-index-contrast photonic crystal layer was incorporated into the laser heterostructures by air-pocket-retaining epitaxial regrowth. Transmission electron microscopy studies confirmed uniform and continuous AlGaAsSb initial growth over the nano-patterned GaSb surface, followed by the development of the air-pockets. The PCSEL threshold current density had a minimal value of similar to 170 A/cm(2) in the 160-180 K temperature range when the QW gain spectrum aligned with the Gamma(2) band edge of the photonic crystal. The devices operated in a continuous wave regime at 160 K. The divergence and polarization of the multimode laser beam emitted from the 200 mu m x 200 mu m PCSEL aperture were controlled by filamentation.