The solution of n-type metal oxide crystals Poisson equation Ⅰ the solution of Poisson equation;

Solving poisson equation by singular hybrid boundary node method;

A new pseudo-spectral method for solving Poisson equation in polar coordinate system;

Using Possion equation,the temperature and temperature distribution in laser crystal were obtained,and the optics path difference(OPD) induced by end-face deformation and total OPD were caculated.

This paper introduces the differeat discrete method with integral poisen equation in which solving the boundary value problems of nonlinear quasi poisen equation can be transformed into linear algebraic equations in constant magnetic fields,which contain nonlinear magnetic medium material.