针对基于射频非平衡马赫-曾德尔干涉仪的光纤布拉格光栅传感器波长解调系统的特性展开研究,实验测量了由非相干光损耗、器件插损及光纤光栅的反射谱宽引起的系统的输出功率衰减。提出选取某个特定微波频率输出强度,针对一定量的样本观测值,采用最大射频强度判别法进行数据处理的完整方法。实验还通过描绘各频率点输出强度最大值得到该波长解调系统频率响应,以119.96 MHz作为调制频率得到0.1692 dB/℃的传感灵敏度。本实验对于非相干光与微波光子滤波器在光纤传感应用过程中的性能改进与可行性研究具有实际参考意义。

The characteristics of the radio-frequency unbalanced Mach-Zehnder interferometer (RF-UMZI) for wavelength demodulation of the fiber Bragg grating (FBG) sensors are studied. The final output power loss of this RF-UMZI due to the incoherent beam loss, insertion loss, and reflection bandwidth of FBG are measured in the experiment. For a certain amount of sample observations of the intensity with a certain microwave frequency, a complete method using the maximum RF intensity discrimination for data processing is proposed. The maximum intensity of each frequency is mapped to obtain the frequency response for notch frequency, and a sensitivity of 0.1692 dB/℃ at 119.96 MHz is obtained. This experiment is of practical reference value in performance improvement and feasibility study for incoherent light and microwave photonics filter utilizing in fiber sensing.