Design and Precision Analysis of Offline Crystal Frequency Tripling Alignment Adjusting System for SG-Ⅱ

A Novel Method for Precision Measurement and Result Optimization of Detuning Angle for KDP Crystals

“…In 2010, Kong et al from the Shanghai Institute of Laser and Plasma Research, Chinese Academy of Engineering Physics (CAEP) used a nanosecond pulsed laser with a beam aperture of about 5 mm and a power density of 1-2 GW/cm 2 to scan the crystal. This measures the optimal phase-matching angle at each point of the crystal and takes the average as a way of reducing the effects of the crystal’s refractive index non-uniformity and the inconsistency of processed shapes [ 17 ]. The Crystal Phase-matching angle Metrology Instrument (CPMI), designed by Pei et al from the Laser Fusion Research Center of the Chinese Academy of Engineering Physics (CAEP) in 2018, used an Nd: YLF laser as the light source and reflected the first-instrumented laser light into the crystal for phase-matching angle measurements through a mirror fixed to a combined X - Z displacement stage, and controlled the stage to change the scanning position as a means of measuring the phase-matching distributions of the crystal at various points [ 18 , 19 ].…”