High efficiency 850 nm wavelength GaAs VCSELs

We report on the optimization of selectively oxidized VCSELs incorporating GaAs quantum wells for multimode emission around 850 nm wavelength. Devices with active diameters between 5 and 12 /spl mu/m show maximum wallplug efficiencies exceeding 55%. Continuous wave operation is achieved up to +185/spl deg/C and the maximum single-mode output power corresponding to 30 dB sidemode suppression ratio is increased to 2.25 mW with layer structures exhibiting reduced index guiding of the optical wave.