波长扫描法布里-珀罗干涉仪的优化设计

Optimization of the Wavelength Scanning F P Interferometer

分析了可用于绝对距离测量的波长扫描法布里－珀罗干涉仪腔内多光束干涉对输出信号的影响， 及由此产生的相位测量误差。研究表明， 通过选择合适的腔端面反射率和参考腔长度可以减小相位测量误差。优化选择的腔面反射率为０．１０～０．１５， 参考腔长为０．９５ ｍ ｍ ， 在１ ｍ ｍ 范围内系统可达到０．０５ μｍ 的测距精度。

The phase errors, resulting from the multi beam interference in the Fabry Perot cavities of the wavelength scanning fiber optic interferometer for absolute distance measurement, are analyzed. It′s proved that selecting the suitable reflectivities of two F P cavities and the length of the reference cavity can reduce the phase errors. In authors′ system, the optimal cavity reflectivity is in the range of 0.10~0.15 and the reference cavity length is about 0.95 mm, the accuracy of 0.05 μm can be obtained in the range of 1 mm.