Enhancement Of Monolayer Graphene Goos-h(?)nchen Shift

The Goos-H(?)nchen(GH)shift is referred to as a tiny lateral shift from the position predicted by the geometrical optics when a finite beam is reflected or transmitted at the interface.In recent years,due to the special and superior mechanical,thermal,optical and electrical properties of monolayer graphene,it has quickly become a research hotspot,and its emergence opens up a new direction for exploring the GH shifts.In this letter,we systematically analyze the Goos-H(?)nchen shifts in graphene-based hybrid structures by using rigorous coupled-wave analysis and the stationary phase method.The main researches of this paper are as follows:Firstly,a hybrid structure based on monolayer graphene and one-dimensional dielectric grating was designed,and the results show that this structure can achieve the GH shift of incident transverse magnetic polarized wave reaches 500l.At the same time,we revealed that the enhancement of GH shift of the hybrid structure originates from the excitation of the guided-mode resonance of the onedimensional dielectric grating.In addition,the GH shift can be enhanced more than 900l by adjusting the chemical potential of graphene,and this structure can realize the enhancement of GH shift at different incident angles by changing the structural parameters of the one-dimensional dielectric grating.Our research results provide a new strategy to enhance other 2D layered materials.Secondly,a graphene-based one-dimensional photonic crystal hybrid structure is proposed,and the results show that this structure can realize the GH shift of incident transverse dielectric polarized wave reaches 80l.Then,we revealed that the enhancement of GH shift of the hybrid structure stems from the one-dimensional photonic crystal structure that enhances the interaction between graphene and light,which significantly affects the change in reflectivity of the hybrid structure.Moreover,the hybrid structure can realize the positive and negative conversion of GH shift sign by selectively adjusting chemical potential of monolayer graphene.It also can achieve the enhancement of the GH shift at different incident angles by changing the structural parameters of photonic crystal.The research results have theoretical guiding significance for the application of graphene hybrid structures in new photoelectric sensors and optical switches.Finally,we theoretically investigate the multilayer structure composed of monolayer graphene,dielectric layer and metal layer together.The results show that this multilayer structure can achieve the GH shift up to-462l for incident transverse magnetic polarized wave.In addition,we attribute the reason for the giant GH shift to the multilayer structure that excites the surface plasmon on the metal.Additionally,by adjusting the chemical potential of graphene,the GH shift can be further enhanced and the sign can be converted,and the maximum positive and negative shifts can reach 947l and-2850l,respectively.By changing the structural parameters of multilayer structure,not only the sign of GH shift can be converted,but also the GH shift can be enhanced at different incident angles.The designed structure realizes the enhancement and sign conversion of GH shift,which provides useful guidance and feasible design proposal for the design and implementation of optical devices,such as photodetectors and sensors.