Minimization of the angular divergence of optical radiation transmitted by a nonlinear layer

An analysis is made of adaptive compensation for the self-interaction of optical radiation in order to minimize its angular divergence in the far-field zone. The compensation quality is governed by the functional of the effective width of the angular spectrum of the beam. A gradient method is used to control the radiation wavefront. Calculations are performed using the aberration-free and quasioptic approximations. The convergence, stability, and speed of the control algorithms and the efficiency of compensation for the angular divergence are analyzed as a function of the following: the nonlinear layer thickness, the nonlinear parameter, the choice of the initial beam focusing, and the control coefficient.