Tunable large omnidirectional photonic bandgap in a one-dimensional photonic crystal comprising elliptical metamaterials based on elasto-optic effect

Recently, researchers predicted angle-insensitive photonic bandgaps (PBGs) in one-dimensional photonic crystals (1DPCs) comprising elliptical metamaterials (EMMs). Empowered by the angle-insensitive property of PBGs, large omnidirectional photonic bandgaps (OPBGs) can be designed. Nevertheless, the wavelength ranges of the large OPBGs in 1DPC comprising EMMs are fixed, which greatly hinders their broad applicability. In this paper, we design a 1DPC comprising EMMs based on elasto-optic effect. As the applied pressure increases from 0 to 30 GPa, the position of the large OPBG can be strongly tuned. Specifically, the short-wavelength edge of the OPBG increases from 1278.46 to 1528.06 nm and the long-wavelength edge of the OPBG increases from 1694.89 to 2246.91 nm. The width of the OPBG increases from 416.43 to 718.85 nm. Our work not only provides an effective approach to dynamically tuning the large OPBGs in 1DPCs, but also promotes the design of tunable omnidirectional reflectors and filters. Graphical abstract