Photonic microstructures as laser mirrors

Deeply etched 1-D third-order Bragg reflectors have been used as mirrors for broad-area semiconductor lasers operating at 975-nm wavelength. From a threshold and efficiency analysis, we determine the mirror reflectivity to be approximately 95%. The design of the GaAs-based laser structure features three [nGaAs quantum wells placed close (0.5 mu m) to the surface in order to reduce the required etch depth and facilitate high-quality etching. Despite the shallow design and the proximity of the guided mode to the metal contact, the threshold current density (J(th)=220 A/cm(2) for infinite cavity length) and internal loss(alpha(i)=9+/-1 cm(-1)) are very low. (C) 1998 Society of Photo-Optical Instrumentation Engineers.