Dynamic modulation of slow light rainbow trapping and releasing in a tapered waveguide based on low-symmetric photonic crystals

Abstract

We propose a numerical investigation of slow light rainbow trapping and releasing in a tapered photonic crystal waveguide which is formed by linearly modifying the structural parameters in low-symmetric photonic crystals. Through dispersion analysis and numerical simulations, the electromagnetic waves of different frequencies in a normalized bandwith of ~5% can be trapped at different positions, as called “rainbow trapping”. Moreover, the tapered photonic crystal waveguide is created on polystyrene subtract, of which refractive index can be adjusted by tuning the external voltage based on electro-optic effect. Therefore, when the applied voltage is properly modulated, the trapped wave will be captured in different positions even released. The structure has broad application prospects in optical switch, wavelength-division multiplexing, and other optical communication devices.