Monolithically integrated surface and substrate emitting vertical cavity surface emitting lasers for smart pixels

Summary form only given. Oxidation of AlO/sub x/ is a selective process over GaAs in an epitaxial stack, and can also be spatially selective over a wafer by defining predetermined areas of a wafer to be exposed to the oxidation process. Using the spatial selectivity of the oxidation we have fabricated monolithically integrated surface and substrate emitting VCSEL´s side by side on a single epitaxial wafer separated by only 125 /spl mu/m. This technology will allow the fabrication of high density arrays of smart pixels with dual communication capabilities in a free space optical system.