A full degree-of-freedom photonic crystal spatial light modulator

TL;DR

This paper introduces a programmable photonic crystal cavity array capable of near-complete spatiotemporal control of optical fields, achieving high precision and fast switching at the fundamental limits of multimode optical control.

Contribution

It presents a scalable, high-precision, full-degree-of-freedom photonic crystal spatial light modulator with innovative fabrication, resonance alignment, and control techniques.

Findings

Demonstrated control of 64 resonators with nanosecond switching

Achieved near-complete spatiotemporal control of optical fields

Operated modes near space- and time-bandwidth limits

Abstract

Harnessing the full complexity of optical fields requires complete control of all degrees-of-freedom within a region of space and time -- an open goal for present-day spatial light modulators (SLMs), active metasurfaces, and optical phased arrays. Here, we solve this challenge with a programmable photonic crystal cavity array enabled by four key advances: (i) near-unity vertical coupling to high-finesse microcavities through inverse design, (ii) scalable fabrication by optimized, 300 mm full-wafer processing, (iii) picometer-precision resonance alignment using automated, closed-loop "holographic trimming", and (iv) out-of-plane cavity control via a high-speed micro-LED array. Combining each, we demonstrate near-complete spatiotemporal control of a 64-resonator, two-dimensional SLM with nanosecond- and femtojoule-order switching. Simultaneously operating wavelength-scale modes near the space- and time-bandwidth limits, this work opens a new regime of programmability at the fundamental limits of multimode optical control.