Use of cholesteric liquid-crystal films in thermophotographic investigations of the output parameters of CW infrared lasers

Cholesteric liquid-crystal films, whose color changed as a result of heating, were used in a thermophotographic study of changes in the output parameters of cw infrared lasers. Photographs of the mode radiation structure and its variation with time were obtained. The time dependences of the coordinates of the center of the beam, power density, and divergence were determined in this way.