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基于正弦相位调制干涉测量是当前国际前沿的高精度光学测量技术,在位移、形貌等测量中得到广泛应用。通常采用傅里叶变换进行频谱分析提取相位参数,测量中需要处理庞大的数据,测量仪器难以快速获得测量结果,严重限制了正弦相位调制干涉的使用范围。为了降低传统频谱分析处理信号的复杂性,采用了滤波技术处理相位信息。在数据处理时直接采用低通滤波器滤除高次谐波成分,通过误差分析可知运用滤波技术处理干涉信号,公式本身引起的误差非常小,最大仅为0.9%;当调制频率波动为0.01Hz时,位移误差最大为0.1nm,误差可以忽略不计。
Sinusoidal phase modulation based on interferometric measurement is the current international advanced high-precision optical measurement techniques, widely used in displacement, topography and other measurements. The Fourier transform is usually used for spectrum analysis to extract phase parameters. In the measurement, huge data needs to be processed, and measurement instruments can not obtain measurement results quickly, which severely limits the use range of sinusoidal phase modulation interference. In order to reduce the complexity of traditional spectrum analysis and processing signals, the filtering technique is used to process the phase information. When the data is processed, the low-pass filter is used to filter out the higher harmonic components directly. The error analysis shows that the error caused by the formula is very small, with a maximum of only 0.9%. When the modulation frequency is 0.01Hz , The maximum displacement error is 0.1nm, the error can be neglected.