Analysis of Refractive-index Distribution of Square Gradient Lens
方形自聚焦透镜折射率分析

MATLAB diffusion partial differential toolbox is used to solve ion diffusion equation with square boundary conditions, and the ion concentration dynamic process is simulated during the ion exchange. The Solution can be played and showed. The Tl+ concentration equation in square class fiber is calculated by variable separation method, the refractive-index distribution of Square GRIN lenses analytic solution is got based on the linear relation between refractive-index and ion concentration. The computation results are in good agreement with the measured ones. It can reflect the refractive-index of Square GRIN well.