Effect of ion beam figuring on laser damage properties of KDP crystal

摘要

Potassium dihydrogen phosphate (KDP) crystals are essential components used in the high power laser applications. Its properties will affect the output power and quality of laser beam directly. To improve the laser-induced damage threshold (LIDT) of KDP crystal, this paper investigated the influence of ion beam figuring (IBF) technology on the laser damage properties of KDP crystal machined by single point diamond turning (SPDT). Firstly, the surface quality and photo-thermal absorption performance of samples were measured after turning and ion beam figuring. Then, the LIDT of crystal of different processing conditions were measured by R-on-1 test method. Finally, the mechanisms that ion beam figuring could improve the LIDT were analyzed and discussed. The experiment results show that ion beam figuring can reduce surface roughness, improve the surface quality as well as lower the absorption of KDP crystal elements, which contribute to increase the laser damage resistance of KDP crystals obviously.