Experimental observation of spatial polarisation separation by absorptive self-focussing

Abstract

An elliptically polarised laser beam tuned to the D1 transition of atomic sodium and having a gaussian-like intensity profile is observed to break-up into a narrower gaussian-like intensity profile surrounded by a circularly uniform annulus, on propagation through a buffer gas broadened sodium vapour. The gaussian-like output has the same polarisation as the weaker component of the input field, while the annular beam has the same polarisation as the stronger component of the input field. This behaviour is consistent with a recently developed theory on self-induced spatial separation of circularly polarised modes. Show more