Fast beam steering by resonant-drive operation of a pixelated MEMS spatial light modulator

Pixelated MEMS spatial light modulators (SLMs) such as digital micromirror devices (DMDs) enable high speed and wide-angle diffractive beam steering with a large-aperture by synchronizing a pulse to mechanical transition of micromirrors, or crossover states. However, the ASIC controlling DMD is designed to minimize the crossover time, and is optimized for power throughput in binary on-off-operation. Since diffractive beam steering is employed during the crossover period, power throughput with continuous-wave (CW) sources is severely limited in diffractive beam steering. To overcome the challenge, we demonstrate a resonant-drive approach that directly excites the micromirror dynamics through the mirror-bias reset (MBRESET) bus, bypassing the pattern-update ceiling of the standard ASIC controller. With analog drive signal, the array operates continuously near mechanical resonance of the micromirror (83–87 kHz) and produces up to 17 observable diffraction orders under 532 nm CW illumination. We quantify performance using energy throughput per steering point and average power per diffraction order, and we measure improvements of 2.51–13.62 times in energy throughput and up to 35.4× in average power per diffraction order relative to ASIC operation for representative drive conditions. Resonant-drive operation removes the synchronization requirement for CW beam steering and enables higher-etendue scanning for applications in particular with CW sources, such as FMCW LiDAR and near-eye displays.