A 1-D heterodyne lens-free optical phased array camera with reference phase shifting

This paper presents the first integrated silicon photonics optical phased array (OPA) receiver with imaging capabilities. A 32-element 1D OPA with an overall aperture size of 96x50 μm^2 is used to generate an electrically steerable "gazing beam". The OPA receiver elements couple the incident light to on-chip waveguides which is processed as a phased array receiver. To minimize signal loss and enhance sensitivity, a heterodyne architecture with phase shifters in the local reference path is utilized. The OPA receiver can provide fully programmable angular selectivity with a grating-lobe-free field-of-view of 30° and a gazing beamwidth of 0.74°.