【摘要】 对环境微振动干扰进行补偿可减小移相干涉测量的误差,其中振动量的检测是实现振动补偿的前提。以声光调制器作为光学移频器,在移相式平面干涉仪中组合成外差干涉测振系统,可以实现光程差微小变化(范围为0到1/2波长)的实时检测。在外差信号处理中采用单片RF/IF相位测量芯片直接对两路40MHz模拟信号进行比相,简化了通常使用的数字测相方法,其精确测相的典型非线性值小于1度。用该系统实际测量了周期性振动和地面冲击振动对干涉仪的影响,获得了干涉仪所受微振动的幅度和相位。更多还原

【Abstract】 In temporal phase-shifting interferometer, the environmental micro-disturbances can lead to wobble of interferoemtric pattern which usually result in erroneous surface measurements. In order to actively compensating for the external vibration, the relative phase variation between the reference arm and the test arm of the interferometer should be measured firstly. Applying acousto-optic modulator for optical frequency shifter, a heterodyne interferometric vibration measurement system is embedded in the phase-shift plane interferometer, and the real-time variation of optical path difference (from 0 to half-wavelength) is processed by a one-chip RF/IF phase detector. In this detector, phase difference of two heterodyne signals at 40MHz is directly measured, which simplified the commonly used digital phase measuring method. The typical nonlinearity of accurate phase measurement is less than 1 degree. The influence of periodical vibration and floor pulse vibration on interferometer is practically measured with system, the amplitude and phase varying of micro-vibration born by the interferometer is obtained.更多还原