SOLID-STATE ARRAY MEMS-BASED BEAM STEERING

Abstract

Solid-State MEMS Spatial Light Modulators (SLMs) stand out in the field of beam steering due to their large etendue and high reliability. Focusing on these two MEMS SLM variants: the Digital Micromirror Device (DMD) and the Phase Light Modulator (PLM), this dissertation expands the boundary of MEMS SLM-based beam steering through three contributions: First, we achieved quasi-continuous steering with PLM by displaying a grating with a non-integer period, enabling beam steering with any arbitrary diffraction angle. Second, we cascaded a DMD for coarse beams steering with a PLM for fine steering, achieving continuous beam steering without unnecessary diffraction orders over a FOV of 40° × 5.6°, which broke the FOV limitation of PLM-only beam steering. Third, we tailored the DMD frame-rate regime: a customed DMD driver board increases refresh to 90 kHz for high-speed beam steering, while an air/liquid damping method halves the mirror transition for low-speed beam steering. Together, these contributions deliver a MEMS-based continuous, wide FOV, diffraction order-free, and ultra-low/high-speed beam steering.