Mode stabilization of 850 nm vertical cavity lasers by Si diffusion & disordering

In this paper we present results on a vertical cavity laser structure which provides fundamental mode operation by way of a fully planar diffusion based process. By selective Si diffusion and disordering, we are able to pattern the upper p-mirror, resulting in suppressed reflectivity of higher order modes relative to the fundamental mode. For a 5 /spl mu/m device diameter, we have obtained a threshold current of 3.8 mA and single mode operation over the entire operating range for the device, with a peak single mode power of 0.63 mW, at a drive current of 6 mA. A 5 /spl mu/m apertured implanted (non-diffused) structure with otherwise similar processing had a threshold current of 5.7 mA, and exhibited multimode operation for output power above 40 /spl mu/W.