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 one-dimensional (1-D) OPA with an overall aperture size of 96 × 50
$\mu \text{m}^2$
is used to generate an electrically steerable “gazing beam.” The OPA receiver elements couple the incident light to on-chip waveguides that 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°.