| Abstract: | With the help of a tensor method, an analytical nonparaxial propagation formula for a twisted anisotropic Gaussian Schell-model
(GSM) beam in free space is derived based on the generalized Raleigh-Sommerfeld diffraction integral. The far-field nonparaxial
propagation expression for a twisted anisotropic GSM beam is also derived. The paraxial approximation is dealt with as a special
case of our general result. Our numerical results show that the nonparaxial propagation properties of a twisted anisotropic
GSM beam are closely related to the initial beam parameters (i.e., twist factor, transverse spot width matrix, coherence width
matrix and wavelength) and the propagation distance. Our formulae provide a convenient and powerful way for studying the paraxial
and nonparaxial propagation of an isotropic or anisotropic GSM beam with or without twist phase in free space. |
