Characteristics of adaptive focusing by the method of phase conjugation in the presence of dislocations in a reflected beam

A numerical study is made of the feasibility of adaptive focusing by a point target using the method of phase conjugation in the presence of wavefront dislocations in the beam reflected by the point target. If a flexible adaptive mirror is used, it is undesirable to minimize the difference between its tilts and the tilts of the wavefront of the reflected beam. The use of piston mirrors is an effective technique provided the piston displacements are governed by the measured values of the differences between the phases at subapertures. The dependence of the density of dislocations on the length of the path of propagation of laser radiation across a turbulent medium is derived.