Polarization independent lithium niobate electro-optic modulator based on guided mode resonance

The active tunable metasurface can flexibly and effectively control the polarization, amplitude, phase and propagation mode of electromagnetic wave. Among them, LiNbO3 metasurface has a unique advantage in integrating electro-optic (EO) tunable components, especially in enabling high-speed spatial light modulation. Here, based on guided mode resonance (GMR), a polarization independent LiNbO3 nanopillar metasurface transmission spatial light modulator is demonstrated from the perspective of free space propagation light modulation. Utilizing GMR, most of the incident light is confined to a 380 nm LiNbO3 layer with the high EO coefficient, enabling fast and efficient light modulation. A clear modulation of 100 MHz is observed by applying an electric bias voltage (+/- 2.8 V) to the LiNbO3 film. The lithium niobate metasurface developed in this study paves the attractive way for compact spatial light modulator. It also embarks on new potential applications in the fields of tunable display, light detection and near infrared imaging.