Net lateral shift of reflected beam due to surface plasmon resonance in Kretschmann configuration

When surface plasmon resonance is excited in Kretschmann configuration, the maximum Goos–Hänchen shift occurs at the resonant angle which is associated with the minimum value of reflectivity, but the maximum angular shift occurs at two incident angles beside the resonant angle. When the reflected beam is detected at Rayleigh range, the maximum net lateral shift of the reflected beam does not encounter the resonant angle and its magnitude is lager than that of Goos–Hänchen shift. Numerical simulation shows that theory agrees well with numerical results when the beam width is large enough.