Tunable Goos-Hänchen shift in a prism-waveguide coupling system with a nematic liquid crystal slab

In this paper, the tunable positive and negative lateral shifts on reflection from a prism-waveguide coupling system with a nematic liquid crystal (NLC) slab are analysed. The large positive and negative Goos-Hänchen shifts are due to the formation of ultrahigh-order modes in the NLC slab. The sign and the magnitude of the lateral shift can be conveniently controlled by adjusting the rotation angle (i.e. the applied driving voltage) as well as by altering the angle of incidence. Numerical simulations confirm the theoretical analysis.