基于高斯光脉冲延迟技术的光纤长度精确测量方法

Precise Measurement Method of Optical Fiber Length Based on Gaussian Optical Pulse Delay Technique

提出了一种基于高斯光脉冲延迟技术的无盲区、高精度光纤长度测量方法。借助光纤延迟环的作用，在高速示波器上可以观察两路具有相对时延的高斯脉冲序列。通过调节脉冲频率可使两路高斯脉冲完全重合，依据此时脉冲频率可计算出光纤长度。脉冲未完全重合则会引入频率测量的误差，而利用脉冲时延与幅度的转换关系，通过脉冲幅度极大值的测量可以精确判断脉冲是否重合。脉冲频率的分辨力达到0．1Hz，从而提高光纤长度测量的精确度。实验中当光源波长为1296nm时，该方法测量2284．34mG．652单模光纤长度的不确定度为0．04m，测量12726．57m的不确定度为0．24m。

A precise and dead-zone-free method of optical fiber length measurement was proposed based on Gaussian optical pulses delay technique. Using optical fiber delay loop, two Gaussian pulses sequences with relative delay were observed in the high-speed oscilloscope. The two Gaussian pulses coincided with each other by adjusting the pulses frequency, and the optical fiber length could be calculated by the frequency. Frequency measurement errors would be induced if the two Gaussian pulses coincided incompletely. Complete coincidence could be judged by measuring the maximum amplitude according to delay-to-amplitude conversion. The frequency resolution achieved 0. 1 Hz leading to high measurement accuracy. Experimental results showed that the uncertainty was 0. 04m for 2284. 34m G. 652 single mode fiber （SMF） , and 0. 24 m for 12726. 57 m SMF when wavelength of the optical source was 1296 nm.