非平衡光纤干涉仪臂差精确测量方法研究

Study on precise measurement of optical path difference of unbalanced optical fiber interferometer

为实现对光纤干涉仪臂差的精确测量,提出了一种采用基于F-P调谐滤波技术的光纤光栅解调系统来精确测量光纤干涉仪臂长差的方法。简要介绍了F-P调谐滤波法的波长解调原理,通过分析非平衡迈克尔逊干涉仪的工作原理,指出了输出干涉谱与臂差之间的关系,进而分析了光纤光栅解调仪对干涉仪臂差进行精确测量原理。实验表明该方法可以实现对干涉仪臂差的精确测量,测量精度可达到2μm。

A precise measurement of optical path difference of optical fiber interferometer is proposed which is based on the fiber Bragg grating demodulation system using Fabry-Perot filtering technology. The principle of Fabry-Perot filtering technology is introduced. By analyzing the principle of unbalanced Michelson＇ s interferometer, the relationship of interferential spectrum and arm length differences are indicated, and the principle of precise measurement of arm length differences by fiber Bragg grating demodulation system are analyzed. The experiment demonstrates that the arm length differences can be measured with a accuracy of 2μm.