Electrically Tunable Metasurfaces for Broadband Beam Splitting Across the Visible Spectrum

Abstract

Tunable metasurfaces for beam-splitting hold potential applications in optical computing, communication, and sensing. However, existing approaches have been demonstrated mostly in gigahertz (GHz) and terahertz (THz) frequency ranges due to the limited scalability of current nanofabrication techniques and the scarcity of suitable materials for efficient metasurfaces in the visible spectrum. In this work, an electrically tunable metasurface for beam-splitting is introduced by combining liquid crystal (LC) cells with a titanium dioxide particle-embedded resin (TiO₂-PER), a scalable, high-refractive-index, low-loss material designed for mass production. By integrating LC cells with a broadband gradient metasurface, dynamic beam splitting is achieved through real-time polarization switching within the LC cells under applied electric fields. Nanoimprint lithography (NIL) with TiO₂-PER, supported by established liquid crystal display (LCD) industry technologies, enables scalable and cost-effective manufacturing, providing a practical solution for next-generation optical devices that integrate electronic and photonic signals.