ICF中可调法布里-珀罗滤波器间距稳定度研究

在神光Ⅱ第9路ICF高功率激光装置中，采用可调法布里-珀罗（F-P）滤波器对幅度调制效应进行补偿，根据补偿装置的技术要求，提出-种应用nm量级精度的电容式位移传感器对可调F-P滤波器间距稳定度进行监控的系统，详细论述了监控系统的结构与工作原理。给出了电容式位移传感器的驱动电路及数据处理与控制软件的设计方案，并对电容式位移传感器的精度进行了标定。实验结果表明，该位移监控系统能够使可调F—P滤波器的间距稳定度保持在15nm／h以内，使幅度调制效应的调制深度优于4％。

abstract {In the 9th laser system of SG II inertial confinement fusion (ICF) facility, tunable Fabry-Perot (F-P) filter is adopted to compensate the FM-AM (frequency modulation-amplitude modulation) effect, according to the technical requirements of compensation device, a precise displacement monitor system using the capacitive displacement sensor with nanometer scale precision to stabilize the spacing of the tunable F-P filter is proposed firstly, then the basic structure and operating principle of the monitor system are analyzed. The design scheme of the driving circuit for capacitive displacement sensor and the data processing as well as the system controlling software are discussed, and the precision of capacitive displacement sensor is calibrated. The experimental results show that the spacing stability of the tunable F-P filter is better than 15 nm/h and the modulation depth of the FM-AM effect is better than 4% by introducing the displacement monitor system.}