Spatial beam shaping for high-power frequency tripling lasers based on a liquid crystal spatial light modulator

We propose and demonstrate a spatial beam shaping method to achieve high-quality near-field for a high-power frequency tripling laser system by using a liquid crystal spatial light modulator (SLM). Considering the nonlinear relationship between the output 3ω intensity and the input 1ω intensity of the frequency conversion system and the transmittance nonuniformity of the whole laser system, we introduce an efficient spatial beam shaping method that improves the output near-field beam quality of frequency tripling laser dramatically. Results show that the near-field peak-to-mean value of the frequency tripling laser improves from 1.83:1 to 1.42:1 after spatial beam shaping within four shots. This method provides effective guidance for spatial beam shaping of high-power frequency tripling laser systems. We demonstrate a spatial shaping method to achieve high-quality near field for high-power 3ω laser.Theoretical and experimental results on 3ω laser beam shaping have not been reported in detail.In the spatial shaping method, we consider the nonlinear relationship between the output 3ω intensity and the input 1ω intensity.