Shifts of Coherent Light Beams on Reflection at Plane Interfaces between Isotropic Media

Abstract

Previous experimental and theoretical work on both longitudinal and transverse shifts of light beams at totally reflecting interfaces is briefly reviewed and the discrepancy between the predictions of the two principal theoretical approaches is discussed. A theoretical treatment, valid for an interface between any two media, is presented. The intensity profile of the reflected beam is the same as that of the incident beam (albeit shifted in the reflecting interface) only for certain polarization states of the incident beam and provided that the reflection parameters of the interface meet certain conditions. If these conditions are not met the reflected beam profile suffers distortion and, possibly, deviation from its expected direction. Because the polarization state of a beam is, in general, altered by reflection, measurements of the shifts over a large range of angles of incidence at a single reflection are needed in order to verify the predictions.