用于真空紫外探测器标定的光学斩波器研究

Optical chopper applied for calibration of vacuum ultraviolet detector

摘要: 为了满足基于低温辐射计的115 nm～400 nm波段探测器绝对光谱响应度高精度标定的需求，研制了一种由斩波片、转轴、伺服电机、U型光电开关、降温组件、支架和控制电路等组成的适用于真空环境的光学斩波器，使其在真空低温环境下将微弱的真空紫外-紫外辐射信号调制为频率已知的交变辐射信号，并由锁相放大器进行测量。实验结果表明，该光学斩波器的频率在80 Hz时的稳定性为±0.05 Hz，满足115 nm～400 nm波段探测器绝对光谱响应度标定对斩波器在10⁻⁴ Pa的真空环境下的使用要求。

Abstract: In order to precisely calibrate the absolute spectral responsivity of detector from 115 nm~400 nm based on cryogenic radiometer, an optical chopper used in vacuum was developed. The optical chopper consisted of blade, rotation axis, servo motor, U-shaped photoelectric switch, cooling module, bracket and controlling circuit could be used to modulate the weak vacuum ultraviolet-ultraviolet (VUV-UV) radiation signal to the alternating radiation signal which the frequency was known in vacuum cryogenic environment, and measured by lock-in amplifier. The experimental results show that the stability of the optical chopper is ±0.05 Hz at the frequency of 80 Hz, which meets the requirements of absolute spectral responsivity calibration of detector at 115 nm~400 nm in the vacuum environment of 10⁻⁴ Pa.