Bragg scattering of stochastic beams in PT-symmetric photonic lattices.

The propagation of a Gaussian-Schell beam through a PT-symmetric optical lattice, whose index of refraction is represented by a sinusoidal type of function, is theoretically investigated. Within the framework of standard coherence theory, one is able to access and elucidate unexpected consequences of the interplay between the spatial coherence properties of the beam and the non-Hermitian nature of the photonic lattice. We describe how one may use a non-Hermitian periodic medium to enhance the spatial coherence properties of a partially coherent beam.