Characteristics of second harmonic generation in CDA and DCDA crystals under thermal self-interaction conditions

An experimental investigation was made of second harmonic generation in CDA and DCDA crystals allowing for the thermal self-interaction of radiation. The dependences of the temperature of the 90° phase matching and of the absorption coefficients on the degree of deuteration of crystals and the dependences of the efficiency of conversion on the average power of the fundamental- frequency radiation and on the length of a nonlinear crystal were determined. An analysis was made of ways of reducing the influence of the thermal self-interaction by the use of astigmatic beams.