Polarization, transverse shifts, and angular momentum conservation laws in partial reflection and refraction of an electromagnetic wave packet

Abstract

We present a solution to the problem of partial reflection and refraction of a polarized paraxial Gaussian beam at the interface between two transparent media. The Fedorov--Imbert transverse shift of the centers of gravity of the reflected and refracted beams are calculated. Our results differ in general case from ones derived previously by other authors. In particular, they obey general conservation law for the beams' total angular momentum but do not obey one-particle conservation laws for individual photons, which have been proposed by Onoda et al. [Phys. Rev. Lett. 93, 083901 (2004)]. We ascertain that these circumstances relate to the accepted in the literature artificial model for the polarized beam which does not fit to real beams. The present paper resolves the recent controversy and confirms results of our previous paper [Bliokh et al., Phys. Rev. Lett. 96, 073903 (2006)]. Besides, a diffraction effect of angular transverse shift of the reflected and refracted beams is predicted.