The Evolution of cosh-Gaussian Beams in strong nonlocal nonlinear Media
R-P. Chen, L-X. Zhong, Q. Wu, C-Q. Dai and G. Zhou
We investigate the dynamical properties of the cosh-Gaussian beams in strong nonlocal nonlinear (SNN) media. Based on the moments method, the evolution of cosh-Gaussian beam widths in the root-mean-square (RMS) sense are analytically obtained. The critical powers that keep the RMS beam widths invariant during propagation with uniform wavefront are given. The analytical solution of the cosh-Gaussian beams in SNN media is obtained by the technique of variable transformation. The numerical and graphical results provide intuitive pictures for the evolution of the cosh-Gaussian beams in SNN media. The cosh-Gaussian beams always periodically transform to cos-Gaussian beams as well as revive during propagation in SNN media, despite the difference of their symmetry and initial power. The RMS beam widths of cosh-Gaussian beams are negatively correlated with the initial powers in the SNN medium.
Keywords: Nonlinear optics, strong nonlocal nonlinear (SNN) media, moments method, Hermite-sinusoidal-Gaussian (HSG) beams