Large positive and negative lateral optical beam shift due to long-range surface plasmon resonance

In this paper, we examine theoretically the beam shift at visible wavelengths on a long-range surface plasmon (LRSP) configuration by using the stationary-phase approach. We report that the lateral beam shift at the resonance of LRSP can be two orders of magnitude greater than a wavelength. It is also found that the sign of the lateral beam shift depends on the magnitude of the intrinsic damping relative to that of the radiative damping. Negative lateral beam shift occurs when the former is larger than the latter.