Enhancement and modulation of photonic spin Hall effect by defect modes in photonic crystals with graphene

Abstract

Photonic spin Hall effect (PSHE) holds great potential applications for manipulating photon spins. However, the efficient control of PSHE in a particular optical structure is still difficult to realize. In this paper, we report enhanced and magnetically tunable PSHE of reflected light in one-dimensional photonic crystals (1D-PC) with a defect layer. By inserting monolayer graphene into the defect layer of 1D-PC, large polarization rotation and strong photon spin-orbit interaction of reflected light are obtained. Due to the optical field confinement by defect mode, the Kerr rotation angle of reflected light is near 90° and the spin-dependent splitting is about 15 times the wavelength at a specific incident wavelength. In addition, a static perpendicular magnetic field increasing from 1T to 11T shows greatly modulation effect on Kerr rotation angle and spin-dependent splitting. These results pave the way toward the design of spin-based photonic devices in the future.