Studies On The Properties Of Coherence And Polarization For Optical Beams Propagating In Niaxial Crystals Orthogonal To The Optical Axis

With the development of science and technology, the laser has been used in information technology, health, industrial processing and defense. With the development of the laser technology, the propagation and transformation of laser beams in optical system and various media have attracted much attention in applications of laser. In recent years, with the increasing number of applications of uniaxial crystals in optics, the propagation of laser beams in uniaxial crystals have attracted much attention. Taking the propagation of laser beams in uniaxial crystals orthogonal to the optical as consideration, the purpose of the present dissertation is to study the propagation properties of the laser beams propagating in uniaxial crystals. The main results obtained are summarized as follows:Based on the angular spectrum representation, the propagation properties of dark hollow beams with circular, elliptical and rectangular symmetries in uniaxial crystals orthogonal to the optical axis are studied. It is shown that the laser beams spread more rapidly in the direction along the optical axis than orthogonal to the optical axis in positive crystal.This dissertation expands the concept of coherent beams propagating in uniaxial to the partially coherent beams, based on the formulae of coherent beams propagating in uniaxial crystals orthogonal to the optical axis and the cross-spectral density of partially coherent beams, the propagation properties of partially coherent flat-topped beams propagating in uniaxial crystals orthogonal to the optical axis. It is shown that the initial coherence length and the n_e/n_o of uniaxial crystals have significant influence on the propagation properties of partially coherent flat-topped beamsThe cross-spectral density matrix of partially polarized and partially coherent beams propagating in uniaxial crystals orthogonal to the optical axis is introduced. And the polarization and coherence properties of partially polarized Gaussian Schell-model beams are studied. It is shown that the degree of polarization decreases with the increase of the n_e/n_o of uniaxial crystals, and the influence of uniaxial crystals on the degree of coherent is not so evident.The generalized Stokes parameters of a stochastic electromagnetic beam propagating through uniaxial crystals are studied. It is shown that hat the uniaxial crystals have little influence on the Stokes parameters S₀ and S₁ , while the Stokes parameters S₂ and S₃ become periodically oscillatory when the stochastic electromagnetic beam propagating through uniaxial crystals.The application of the Wigner distribution function matrix of the partially polarized and partially coherent beams through uniaxial crystals orthogonal to the optical axis is illustrated with the stochastic electromagnetic beams. It is shown that the propagation of beams in uniaxial crystals orthogonal to the optical axis can be described by the simple algebra transformation of Wigner distribution function.