Propagation of Lorentz-Gaussian elliptical multi-Gaussian correlated Schell-Model beam in uniaxial crystal

Abstract

The evolution behavior of the intensity profile, beam spreading, and spectral degree of coherence of the Lorentz-Gaussian elliptical multi-Gaussian correlated Schell-Model beam propagating in uniaxial crystal are studied. The expression of the cross spectral density of the beam in uniaxial crystal is obtained based on Huygens-Fresnel integration, and the expressions of spectral coherence and root mean square (rms) beam width are derived. The beam spot is circular or elliptical while the ordinary and extraordinary refractive indices of the crystal are equal or unequal, respectively. The ellipticity of the light spot is affected by the Lorentz parameters. The larger the ratio of ordinary to extraordinary refractive index in uniaxial crystal is, the larger the spectral coherence of beam and rms beam waist width is. The spectral coherence increases with the increase of the Gaussian beam waist and the decrease of the Lorentz parameters. The rms beam width of the beam increases with the increase of the Gaussian beam width and Lorentz partial parameters. With the increase of the transmission distance, the influence of the light source parameters on the rms beam width gradually weakens. The total number of terms of multi-Gaussian correlated Schell-Model (MGSM) source and the spatial coherence lengths add additional degree of freedom for adjusting the spot pattern inside crystal.