Abstract
In the harmonic generation using nonlinear optical crystals, it is well known that the frequency-conversion efficiency is very sensitive to temperature of the crystal, and decreases with irradiation time. In the previous study, we have investigated laser absorption dependence of SHG conversion efficiency theoretically with one-dimensional model, supposing uniform intensity beam. In this paper, two-dimensional analysis was carried out with an axisymmetrical model based on the previous one-dimensional model. The variation of the conversion efficiency of KDP crystal and the profile of output beam was analyzed quantitatively during repetition irradiation of pulse laser. Temperature control of the crystal was also applied theoretically, and its reduction effect for decline of conversion efficiency was investigated.
