All dielectric metasurface based tunable optical modulator: Design and analysis

•Fano resonance in high index contrast all-dielectric metasurface.•Broadband tunability of 25 nm and modulation depth of 90 %.•Electrically controlled high birefringent liquid crystal for optical tuning. In this article, we propose the design and analysis of all-dielectric metasurface based tunable optical modulator. The metasurface structure consists of split silicon arcs mounted over the indium tin oxide layer and the silica substrate. The nematic liquid crystal is used for tuning the Fano resonance peak of the metasurface and is filled between two indium tin oxide layers. The numerical investigation of the proposed metasurface for electro-optic modulation shows the modulator has a broadband tunability of 25 nm and modulation depth of 90 %. We have also numerically investigated the variation of the Fano resonance peak arising due to the fabrication non-uniformities in the thickness, width and the split gap of the silicon arc.