Manifestation of coherence decay of optical vortices on scattering through photorefractive SBN crystal

Abstract

We have investigated scattering of optical vortices via beam fanning as they propagate in photorefractive SBN crystal. The measurements show that the power decay of the vortex through the crystal depends on the order of the vortex. This decay for optical vortices is compared with that of the Gaussian laser beam and it is found to be faster than the vortices. The experimental results are explained using the dependence of the two-wave mixing or beam coupling in the photorefractive materials on the degree of coherence. Furthermore, the coherence dependence of the beam fanning has been verified with partially coherent light.