Research on the Nonlinear Absorption Coefficient of 98% Deuterated DKDP Crystal at Fourth-Harmonic-Generation Wavelength

A series of 98% deuterated DKDP crystals were grown in solutions with different pD values (2.9, 3.3, 3.8, and 4.3) using the rapid growth method. Samples cut along z-direction fourth-harmonic-generation (FHG) direction which contained both pyramidal prismatic regions. The nonlinear absorption (NLA) coefficient ? was obtained Z-scan method operated at FHG wavelength (266 nm) a picosecond Nd:YAG laser. According to results, 266 nm could be identified as two-photon absorption. crystal solution 3.3 value higher than those other under laser fluence. results also indicated that device samples should prepared from region due its lower value. This work will help optimizing application elements high-power systems.