基于激光相位法测量光纤长度

Optical fiber length measurement based on laser phase method

针对百米内光纤长度的测量设计了一种新型的激光测量光纤长度系统。该系统依据相位式激光测距原理,通过对激光光强的调制、利用光在传输过程中的相位延迟与光纤长度之间的线性关系测量光纤长度。激光的调制发射由正弦信号与基准电压经过求和电路实现,相位延迟量由探测器接收信号与调制信号经过模拟鉴相后获得,AD数据采集后由单片机处理及显示。实验表明,系统测量光纤长度的稳定度小于0.66 m,最大绝对误差小于0.25 m,最大相对误差小于1.2%。利用该方法设计的光纤长度测量系统电路简单有效、功率小,且具有较高的测量精度和稳定性。

A new type of fiber length laser measuring system is designed to measure the fiber length in 100 meters. Based on the principle of laser distance measurement, modulating the intensity of laser light, the length of the fiber is measured by the linear relationship between the phase delay and the length of the optical fiber. The modulation of the laser is realized by the sine signal and the reference voltage. After the detector receives the signal and the modulation signal passes through the analog phase demodulation , phase retardation that is related to the length of the optical fiber is obtained, and the data is processed by the MCU after AD acquisition. The stability of the system is less than 0.66m; the maximum absolute error is less than 0.33m; the maximum relative error is less than 1.6%. The optical fiber length measurement system designed by this method is simple and effective, low in power, and high in accuracy and stability.