Change in lasing parameters near a crystal-matrix phase transition

Lasing processes involving local levels of impurity atoms or ions are considered, and the characteristics of stimulated emission (SE) near a crystal-matrix phase transition are analyzed. Allowance is made for the effects of critical fluctuations in the transition parameter, and a determination is made of the anomalous temperature dependence of SE for a temperature of approximately the phase transition temperature and the lasing frequency. It is also shown that the results presented by Klimontovich (1980) and Emel'ianov and Klimontovich (1978) have only a limited range of application and often do not yield a satisfactory description of the experimental findings.