在利用正弦相位调制菲佐干涉仪进行测量时, 由于菲佐板及待测物体表面对入射光的多次反射而产生多光束干涉, 干涉信号的强度随相位变化不是严格的余弦分布。按照双光束干涉的算法进行相位信息提取, 会引入一定的误差。以正弦相位调制菲佐干涉仪纳米精度微小位移测量为应用背景, 分析多光束干涉情况下该干涉仪信号解调算法的误差, 进而对干涉仪的相关参数进行优化, 并通过误差补偿对测量结果进行修正, 有效减小了多光束干涉产生的影响。

A novel optical excitation and detection apparatus was used to investigate the characteristics of silicon micro-resonators, which was activated into vibration by a laser beam irradiation. The beam diameter of the excitation light was less than 10 'mu'm. The vibration amplitude of the resonator was detected by the interferometer with high resolution of 0.1 nm and measurement repeatability of less than 3 nm. The resonant frequency of the micro-resonator was obtained to be 8.75 kHz with full-width at half-maximum (FWHM) of 0.18 kHz. It is shown that the method is useful and reliable for measuring micro-displacement and micro-vibration of minute objects with nanometer accuracy.

A new quality map for quality-guided phase unwrapping is presented. The quality map is derived from the wrapped phase map directly and can reflect phase quality accurately. It is demonstrated that the proposed quality map is a good phase-quality indicator, with which the quality-guided unwrapping algorithm can retrieve a reliable phase profile.

A double sinusoidal phase modulating (SPM) laser diode interferometer for thickness measurements of a transparent plate is presented. A carrier signal is given to the interference signal by using a piezoelectric transducer, and the SPM interferometry is applied to measure the thickness of a transparent plate. By combining the double-modulation technique with the Bessel function ratio method, the measurement error originating from light intensity fluctuations caused by the modulation current can be decreased greatly. The thicknesses of a glass parallel plate and a quartz glass are measured in real time, and the corresponding experimental results are also given.