High performance GaAs/AlGaAs vertical-cavity surface-emitting lasers designed for cryogenic applications

The slope efficiency (/spl eta//sub s/) and the output power (P/sub out/) of proton-implant-isolated AlGaAs/GaAs vertical-cavity surface-emitting lasers (VCSELs) improve dramatically as the temperature is decreased, with /spl eta//sub s/>90% at 77 K, compared to /spl eta//sub s//spl ap/20% at room temperature. This suggests that the VCSEL can be a very efficient device for cryogenic applications. In this paper we report the first VCSEL that has been optimized for operation near 77 K, with characteristics that are superior to those of VCSELs operating at room temperature, including high output power (P/sub out/=22 mW), high power conversion efficiency (/spl eta//sub d/=32%), high slope efficiency (/spl eta//sub s/=75%-95%), low threshold voltage (V/sub th/=1.75 V) and current (I/sub th/=2 mA), and low power dissipation (P/sub d/<10 mW for P/sub out/=2.5 mW) for a 20 /spl mu/m diameter device.