基于相位调制器与Fabry-Perot干涉仪的激光多普勒频移测量方法

提出了一种激光多普勒频移测量方法, 此方法利用正弦相位调制使信号光在原频率成分基础上产生正负一阶边带, 再由Fabry-Perot干涉仪对调制光振幅和相位进行调整, 使其产生固定频率的拍频信号, 利用此拍频信号的振幅随频率变化而变化的性质来进行多普勒频移测量. 通过理论分析证明该方法具有很高的测量精度, 加工装调难度不大, 兼顾了普通相干与非相干探测方法的优势. 另外通过实验证明该方法的正确性与可行性, 并通过与普通非相干方式比较发现该方法在测量精度上可以提高 约1个数量级. 关键词： 多普勒频移 相位调制 Fabry-Perot干涉仪 拍频

Laser Doppler shift measuring method based on phase modulater and Fabry-Perot interferometer

A different method of laser Doppler shift measurement is proposed. By using the sinusoidal phase-modulation, the plus and minus one-order sidebands beside the original frequency component in signal light are generated. And a beat frequency signal with fixed-frequency is present when the amplitude and phase of the modulated light are turned with Fabry-Perot interferometer. The characteristic of the amplitude of this beat frequency signal changing with the frequency is used to measure the Doppler shift. By theoretically analyzing, it can be concluded that this method can possess the advantages of both the normal coherent and non-coherent methods and also has the merits of high measuring accuracy and easy fabrication. The validity and feasibility of this method are verified experimentally, and its measurement accuracy is found experimentally to be one order of magnitude higher than that of the normal non-coherent method.
Keywords： Doppler shift phase-modulating Fabry-Perot interferometer beat frequency