Effect of laser beam amplitude profile on second harmonic generation efficiency
V.O. Troitskii
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: second harmonic generation, nonlinear wave equation, numerical method, optimal focusing, optimal laser beam amplitude profile
Abstract
Efficiency of laser radiation harmonic generation in nonlinear crystals is among topical issues in applied nonlinear optics. This work theoretically studies the second harmonic generation (SHG) in a converging (focused into a crystal) laser beam. The influence of the amplitude profile (AP) of fundamental laser radiation beam (before a lens) on the SHG efficiency and on optimal focusing and wave detuning parameters is estimated for the first time. It is ascertained that the optimal values of focusing and especially wave detuning parameters vary in very wide ranges depending on the AP. Strong influence of the AP on the effective aperture length, which mainly limits the SHG efficiency, is shown. Optimization of the AP enables increasing the SHG efficiency by no more than ~ 10%.
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