Adaptive focusing of high-intensity light beams over short paths

Numerical experiments were used to analyze the efficiency of adaptive control of the wavefronts of light beams traveling under conditions of steady-state wind refraction over paths amounting to 0.1 of the diffraction length. The equations describing the propagation of the light waves emitted and scattered by an object were solved in a lens system of coordinates, which made it possible to increase considerably the reliability of numerical prediction. The results were used to propose wavefront control by an algorithm for modified phase conjugation based on storage of a phase profile ensuring the best compensation of nonlinear distortions in all the preceding iterations. This algorithm was found to increase the concentration of the field on an object by 40–45% compared with nonadaptive focusing.