A model of the random phase screen in the problem of the thermal selfdefocusing of light
Abstract
The twodimensional problem of the thermal selfdefocusing of light in a fixed medium is examined using the approximation of geometrical optics. An exact solution of the Cauchy problem for this approximation is obtained. Based on the solution of the Cauchy problem, an exact solution is obtained for the mean intensity and phase gradient of the beam behind a random phase screen (the average over the random initial phase). This model also describes the thermal selfdefocusing of a spatially incoherent beam. It is shwon that, in order to obtain finite expressions for the mean square intensity, it is necessary to exceed the boundaries of the approximation of geometrical optics.
 Publication:

Zhurnal Eksperimentalnoi i Teoreticheskoi Fiziki
 Pub Date:
 August 1983
 Bibcode:
 1983ZhETF..85..461O
 Keywords:

 Geometrical Optics;
 Light Beams;
 Phase Deviation;
 Random Processes;
 Thermal Blooming;
 Cauchy Problem;
 Incoherent Scattering;
 Light Modulation;
 Luminous Intensity;
 Nonlinear Optics;
 Screen Effect;
 Lasers and Masers