Enhancement of four reflection shifts by a three-layer surface-plasmon resonance

We investigate the effect of a surface-plasmon resonance on Goos-Hänchen and Imbert-Fedorov spatial and angular shifts in the reflection of a light beam by considering a three-layer system made of glass, gold, and air. We calculate these spatial and angular shifts as functions of the incidence angle showing that they are strongly enhanced in correspondence with the resonant angle. In particular, we find giant spatial and angular Goos-Hänchen shifts for the p-wave light close to the plasmon resonance. We also predict a similar but less pronounced resonant effect on spatial and angular Imbert-Fedorov shifts for both s-wave and p-wave light.