Influences of nonuniform laser medium on phase and intensity distributions of laser modes

Nonuniform laser medium will cause the variations of phase and intensity distributions of laser modes. It is difficult to solve the wave equations associated with nonuniform laser medium. In this paper, the potential function of nonuniform laser medium was approximately expressed by the primary three items of its Taylor series expansion, and then coupled into the special function in Helmholtz equations describing the laser modes in a resonator. According to the boundary conditions of a typical resonator, we derived the expression for the eigen-solutions of laser modes, the expression for the output laser power, and the expressions for the relations between nonuniform laser medium and phase/intensity distributions of laser modes. Applying the derived expressions in the nonlinear curve-fitti