微波电光调制BOTDR系统中参考光功率稳定控制

摘要

在基于微波电光调制的布里渊光时域反射分布式温度传感系统中，使用微波扫频会造成电光调制器输出的参考光功率波动，根据相干检测的原理，参考光功率的波动会影响到测得的后向布里渊散射信号的功率，将直接影响布里渊散射谱的测量精度，导致较大的温度测量误差。因此，提出一种根据电光调制器输出光功率反馈调节微波源功率，以稳定布里渊光时域反射系统参考光功率的方法。实验结果表明，该方法可以有效抑制电光调制器输出的一阶边波带峰值功率的波动，使系统的温度测量精度从6℃提高到了2℃。%In the distributed temperature sensing system of Brillouin optical time domain reflectometer based on the electro-optical modulation, the power of reference light exported from the electro-optic modulator will fluctuate while using microwave sweeper. According to the principle of correlation detection, the fluctuations of reference light power will affect the power of Brillouin scattering light,and it will cause large error in temperature measurement. Therefore, a method that can adjust the microwave power based on the output light power feedback of electro-optic modulator has been proposed to keep the power of reference light of Brillouin optical time domain reflectometer stable. The experimental results show that the method can suppress the fluctuation of the first-order edge wave band peak power exported from the electro-optic modulator effectively, and the temperature measuring accuracy has been increased from 6℃to 2℃.