Optical phased arrays based on silicon and GaAs photonic waveguides

Optical phased arrays can achieve inertialess, high-resolution, flexible beam steering required by a broad range of applications, such as laser radar, free space optical communication and interconnect, and laser projection displays. In this paper, we study the SOI and GaAs waveguide optical phased arrays (WOPAs) comparatively. The principle of the phase shifter is investigated based on the thermo-optic effect in silicon waveguides and electro-optic effect in GaAs waveguides. The propagation properties of optical field in the two kinds of WOPAs are studied numerically, including the guided modes, the propagation of optical field in a single waveguide and the coupling properties of optical field in waveguide arrays. We also analyze the performance of the two kinds of WOPAs. Silicon WOPAs show superiorities of low propagation loss and wide beam scanning range, while GaAs WOPAs show superiorities of fast beam scanning speed. This research provides a valuable reference for the chip design of optical phased arrays.