New algorithm for numerical simulation of the propagation of laser radiation

A new more accurate calculation algorithm (with a variable grid-mesh size) is proposed for the propagation of radiation considered in the paraxial approximation based on the Fresnel - Kirchhoff formula. The algorithm was used to develop the FRESNEL program intended for simulation of the propagation of radiation through laser systems. Examples of calculations carried out with the new algorithm are given and they are compared with the traditional method