提出了一种基于双相移光纤光栅和光电振荡器的传感解调方法。该方法融合了光纤光栅传感技术与微波光子技术,其中光纤光栅同时作为传感探头及光电振荡器中的微波光子滤波器组成单元,当外界待测量改变光栅特性时,光电振荡器产生的微波频率也将随之改变,且环境温度变化并不会对微波频率造成影响,有效避免了交叉敏感。同时,阐述了通过光电振荡结构将光栅波长变化转换到微波域进行解调的方案及优点,进而得到了实验搭建的基于此光栅的双通带微波光子滤波器测试结果,构造了基于双通带微波光子滤波器的光电振荡环,实验结果表明,该系统的传感解调灵敏度约为36 MHz/με。所提方法为光纤光栅传感的高速、高分辨率解调提供了新思路,推动了光纤传感的实用化进展。

Herein, we propose a method for interrogating a fiber grating sensor using a dual-phase-shifted fiber grating and an optoelectronic oscillator (OEO). Combining the advantages of fiber grating sensing technology and microwave photonic technology, fiber gratings in a system serve both as sensing probes and as filtering units in a microwave photonic filter of the OEO. When the measurand changes the features of the sensing fiber grating, the frequency produced by the OEO also changes. This is not influenced by varying environmental temperatures, thus avoiding the cross-sensitivity problem of fiber grating sensors. Through the OEO, the wavelength change of the grating is reflected as a corresponding change in the microwave frequency. Furthermore, we experimentally demonstrate such a dual-passband microwave photonic filter using the phase-shifted fiber grating and construct an OEO ring based on the filter. Our experimental results show that the proposed system can provide an interrogation sensitivity of about 36 MHz/με. The implementation of this device holds promise for the development of a novel method of interrogating fiber grating sensors to achieve high-resolution and high-speed measurements. The proposed method can also help promote further developments in practical applications of optical fiber sensing technology.