Large Goos–Hänchen shift for different modes in metal–insulator–metal waveguide with electro-optic material

We study the large Goos–Hänchen (GH) shift for different guided mode in the metal–insulator–metal waveguide by the adjusting of electro-optic (EO) material permittivity. Stationary-phase method is used to calculate the GH shifts for different guided mode propagating in the waveguide, and simulation results show that the increase of the upper-cladding metal layer reduces the GH shift and the critical incident angle. In addition, the GH shift of higher-order mode has less sensitivity to the change of thickness of upper-cladding metal layer but better sensitivity to the incident angle than lower-order mode. These different properties of GH shift for different modes can be used to design detectors with different functions.