Thermal self-focusing in a proustite crystal and its thermal properties

The probing beam method was used in an investigation of a steady-state thermal self-focusing in proustite induced by CO₂ laser radiation. The dependence of the nonlinear divergence of a probing He–Ne laser beam on the CO₂ laser radiation power was determined. The expression for the nonlinear divergence yielded the thermal conductivity. The bulk specific heat was also determined. Estimates were obtained of the critical power and energy needed for the development of self-focusing in proustite.