Misaligned optical resonator with a lens-like medium

A description is given of a method of calculating optical resonators based on solving a parabolic equation. By applying this method to unstable resonators with lens-like media, it is possible to describe the mode structure with misaligned mirrors (in addition to finding the known properties). Relationships between the spatial characteristics of the laser beam and the misalignment parameters of the mirrors and inhomogeneity of the medium are determined.