提出并设计了基于侧边抛磨传感臂结构的光纤Mach-Zehnder干涉结构, 并对其温度传感特性进行了研究。通过将两支分光比为50∶50的1×2端口光纤耦合器相对熔接, 构建光纤Mach-Zehnder干涉结构, 采用单模光纤作为干涉结构的参考臂。基于侧面研磨技术在3m长纤芯/包层尺寸为9/125μm的单模光纤上进行抛光, 抛光时长为5h, 制备了研磨长度为20mm、深度为50μm的光泄露窗作为干涉结构的传感臂, 提高传感器的灵敏度。采用宽带光源对Mach-Zehnder干涉结构的透射光谱进行测试, 干涉周期为0.66nm。实验中对传感结构进行了温度测试及分析, 选取波谷位置为1551.48nm作为测试点。在25~60℃的升温范围内干涉条纹向长波方向移动3.97nm, 传感器的温度灵敏度为115.4pm/℃。不同温度下对应波谷的波长位移量与外界温度呈现良好的线性关系, 线性度为0.9940, 功率漂移小于1.66dB, 具有较好的功率稳定性。

The fiber Mach-Zehnder interference structure based on the side polishing sensor arm structure was proposed, and its temperature sensing characteristics was studied. By fusing two 1×2 port fiber couplers with spectral ratio being 50∶50, the interference structure was constructed, and the single mode fiber was used as the reference arm. Based on the side polishing technology, the single mode fiber with 3m long core/cladding size of 9/125μm was polished for 5hours, and the optical leakage window with polishing length of 20mm and depth of 50μm was prepared as the sensing arm of the interference structure to improve the sensitivity of the sensor. The interference structure was tested with a broadband light source, and the interference period was 0.66nm. The experiment of the temperature sensing structure was carried out and the tested valley was chosen at 1551.48nm when hearting from 25 ~ 60℃, the interference fringes moved towards long wave by 3.97nm and the temperature sensitivity is 115.4pm/℃. The linearity is 0.9940, the power drift is smaller than 1.66dB, which had a good power stability.