Peng Xiaoqiang

Study on the feasibility of ion beam figuring on DKDP crystal

In order to explore the feasibility of ion beam figuring (IBF) on DKDP crystal, the DKDP crystal machined by single point diamond turning (SPDT) was processed by IBF. This paper investigates the influence of IBF on DKDP crystal. Firstly, the surface quality and the photo-thermal absorption of DKDP crystal were measured respectively after SPDT and IBF. Then，the laser-induced damage threshold (LIDT) of two different processing crystals were tested by R-on-1 method. Finally, the mechanisms that the effect of IBF on LIDT were analyzed and discussed. After processing， the DKDP crystal remained intact. The surface quality satisfied the frequency tripping crystal requirement. However, due to the environmental impact, DKDP crystal had deliquescence, which contribute to decrease the LIDT of DKDP by 27.5%. IBF on DKDP is feasible，it is necessary to control the processing environment to avoid the crystal deliquescence.