Giant enhancement of Goos-Hanchen shift in graphene-based dielectric grating

The Goos-Hanchen (GH) shift is a sizable lateral shift when the reflected beam comes across an interface between two media and suffers from the total internal reflection. The emergence of 2D layered materials opens a new realm for exploring the GH shifts. By combining rigorous coupled-wave analysis and the stationary phase method, we theoretically investigate the GH shift of the hybrid structure composed of monolayer graphene and 1D dielectric grating layer together. It is found that a sharp peak appears in the spectrum of GH shift, whose magnitude is significantly enhanced and can be up to 500 times of incident wavelength. The main reason for the enhancement of the GH shift results from the excitation of the guided-mode resonance in the dielectric grating layer. In addition, the GH shift here can be controlled by selectively adjusting chemical potential of monolayer graphene as well as the geometrical parameters of the dielectric grating layer. Our results suggest an alternative method for realizing the enhanced and controllable GH shift in monolayer graphene by virtue of the dielectric grating layer, offering promising opportunities for high-resolution sensor and imaging detection applications.