High-speed, phase-dominant spatial light modulation with silicon-based active resonant antennas

Abstract

Spatiotemporal control of optical wavefronts is of great importance in numerous free-space optical applications including imaging in 3D and through scattering media, remote sensing, and generation of various beam profiles for microscopy. Progress in these applications is currently limited due to lack of compact and high-speed spatial light modulators. Here we report an active antenna comprising a free-space coupled asymmetric Fabry–Perot resonator that produces a phase-dominant thermo-optic modulation of reflected light at frequencies approaching tens of kilohertz. As a proof of concept for spatial light modulation, we demonstrate a 6 × 6 array of such active antennas with beam deflection capability. The robust design of our silicon-based active antenna will enable large-scale integration of high-speed, phase-dominant spatial light modulators.