无限非局域热非线性介质中高斯光束传输的变分研究

通过简化由薛定谔方程与泊松方程组成的耦合方程组,得到描述无限非局域热非线性系统所对应的拉格朗日密度,进而利用变分原理对高斯光束在该系统中的传输进行分析,得到高斯光束的束宽、振幅和波前曲率的演化方程,特别是利用势函数分析了形成空间孤子的条件与束宽变化规律.最终数值地验证了该变分计算结果,表明高斯函数是该非局域介质中空间孤子轮廓的一个很好的近似,从而为孤子的相互作用及其偏转特性提供了依据.

Variational study of Gaussian beam in infinite nonlocal nonlinear thermal media

The Lagrange density for infinite nonlocal nonlinear system is got by simplifying the coupled equations which is composed of Schrodinger equation and Poisson equation, and by analyzing the transmission of Gaussian beam in this system using the variational principle, the evolution equations which describe the beamwidth, amplitude and wave-front curvature of Gaussian beam are achieved, especially the condition to form spatial soliton and the rule of the beamwidth evolution are analysized using potential function. Finally, the results of variational calculations are confirmed by numerical simulation, which implying that Gaussian function is a good approximation to the spatial soliton profile in the infinite nonlocal nonlinear thermal media, and the foundation for the interaction and deflection characteristic of solitons is provided.