Design and Analysis of a Novel Phase-Shifted Bragg Grating for Bloch Surface Waves

A novel phase-shifted Bragg grating (PSBG) for Bloch surface waves (BSWs) propagating along the interface between a semiconductor thin layer and a multilayer stack is proposed. This structure is composed of a set of a special ridge fabricated on a multilayer stack supporting a Bloch surface wave. The multilayer stack is periodic, with the unit cell composed of two layers with different materials and thicknesses. The light confinement capability and transmission properties of the proposed structure are investigated in the wavelength range of 1450-1650 nm by using the finite-element method and finite-difference time-domain method. Compared to existing PSBG structures based on surface plasmon polaritons waves, the proposed configuration does not include any metal and the absorption losses upon propagation of the surface wave are negligibly small. Simulation results also indicate that the proposed structure exhibits outstanding transmission properties. The proposed PSBG for BSWs could be applied in narrow bandpass filtering, all optical computing, and enable on-chip integration photonic circuits.