Manipulating Dual Bound States in the Continuum for Efficient Spatial Light Modulator

Spatial light modulators (SLMs) that could control diverse optical properties are highly demanded by many optoelectronic systems. Recently, the integration of nonlinear χ(2) materials and metasurfaces has been recognized as a promising strategy for next-generation SLMs. However, their modulation efficiency still encounters challenges due to low quality factor and weak light-matter interaction. Here, we demonstrate an efficient SLM by manipulating the dual bound state in continuum (BIC) with the assistance of a binary-pore anodic alumina oxide template technique. The coexistence of symmetry-protected BIC and Fabry-Pérot BIC is obtained by a desirable sandwich configuration with a BIC metasurface and EO polymer, which efficiently restrain radiative loss and generate a strong quasi-BIC resonance. The assembled SLM with large absorption and Q-factor delivers a modulation depth of 77% and an f3 dB of nearly 100 MHz. This dual BIC metasurface provides potential for applications including switches, LIDAR, augmented and virtual reality, and so on.