Calculation of laser resonator characteristics

A method is proposed for solving the integral diffraction equation for a laser resonator, which does not use the Fox-Li iteration approach but is based on a system of linear algebraic equations. It is shown that this method makes it possible to calculate in a single run a large set of resonance modes and of the corresponding losses, and to carry out calculations in the case of arbitrary Fresnel numbers. The method is economical in respect of the computer time.