Optical design choices for VCSEL-based free-space optical interconnects

摘要

We develop a model for a clustered free-space optical interconnect and use this to determine the maximum array density which can be achieved. We assume that the sources are multimode vertical cavity surface emitting lasers and that refractive microlenses are used to collimate the VCSEL beams. We also assume that the relay lenses are diffractive lenses with a quadratic phase profile. We find that for short interconnect distances, the maximum channel density is limited by the speed of the relay lenses, but that as the interconnect distance increases geometric aberrations are the limiting factor. We also determine the interconnect distance below which a micro-channel relay is more suitable and above which a single lens solution is adequate.