Electrically tunable Fano resonances in liquid crystal-based dynamic metasurface at telecommunication wavelengths

Dielectric metasurface has become a versatile platform for light manipulation. Due to its subwavelength feature size, the metasurface can induce optical resonances with tailored characteristics, such as Fano resonance with asymmetric line shape. Moreover, resonance tuning is desired in many devices, such as spatial light modulators and light sources. However, the electrically controlled Fano resonance in liquid crystal-based dynamic metasurface has not yet been fully explored. This work demonstrated tunable Fano resonance near 1550 nm in silicon metasurface that was immersed in liquid crystal. Although no additional alignment treatment was performed, the liquid crystal alignment provided entirely by metasurface was sufficient to induce a blue shift of more than 40 nm after applying a peak voltage of 10 V. A lower-frequency resonance with the origin of bound states in the continuum was also identified and verified through simulation. This work demonstrates the potential of liquid crystal-based dynamic metasurface for resonance tuning, paving the way for more advanced dynamic resonance engineering.