Twisted-free ten-parameter family of partially coherent general anisotropic Gaussian Schell model (TF-AGSM) beams

Abstract

We investigate the twist properties of the ten-parameter family of partially coherent general anisotropic Gaussian Schell model (AGSM) beams passing through first-order optical systems. By utilizing the generalized Huygens-Fresnel diffraction integral for asymmetric first-order optical systems, the explicit twist expressions for the principal axes of intensity distribution, transverse coherence distribution and the principal curvatures of phase front in the cross-spectral density function of AGSM beams are obtained. In some special cases when the beams are the twist Gaussian Schell-Model, Gaussian Schell-Model, Li-Wolf and Gori-Guattari beams, our results reduce to well known expressions. It is shown that, under some conditions, although the ten parameters are all not zero and any one of the intensity distributions, transverse coherence distribution and the phase front has its independent principal axis, the beam spot does not twist when the beam passing through free-space. As a result, special partially coherent beams called the twisted-free ten-parameter family of partially coherent general anisotropic Gaussian Schell model (TF-AGSM) beams are introduced and their properties are discussed.