纤芯失配熔接的高灵敏度光纤折射率传感器  

High-sensitive fiber-optic refractometer constructed by core-diameter-mismatch welding

作　　者：高平安[1] 荣强周[1] 孙浩[1] 忽满利[1] 

机构地区：[1]西北大学物理系,陕西西安710069

出　　处：《应用光学》2013年第3期542-546,共5页Journal of Applied Optics

摘　　要：提出并实验验证了一种基于马赫泽德干涉仪(MZI)的高灵敏度光纤折射率(RI)传感器。传感头由一段单模光纤(SMF)夹熔在两段较短的细芯光纤(TCF)中组成TCF-SMF-TCF结构,其总长度为9mm。由于光纤纤芯失配导致的纤芯模和包层模发生干涉,干涉谱对传感头外部折射率的响应极其敏感。使用该传感器检测具有不同折射率的甘油水溶液,实验结果显示:传感器干涉谱的共振波长随环境折射率的增大向长波方向漂移,其折射率灵敏度在1.33RIU～1.38RIU范围内约为159nm/RIU。该传感器具有结构简单、易于制造、成本较低、灵敏度高、抗电磁干扰能力强等优点,在生物化学与环境监测等领域具有较大的应用潜力。A high sensitive refractive index （RI） sensor based on Mach-Zehnder interferometer （MZI） is proposed and experimentally demonstrated. The sensing head is formed by a single- mode fiber （SMF） sandwiched between two short sections of thin-core fibers （TCFs）, and the length of TCF-SMF-TCF MZI configuration is about 9 mm. A well-defined interference pattern is obtained as the result of fiber core mismatch and core-cladding modes interference. The se- lected interference spectrum is extremely sensitive to the response of ambient RI. Using the proposed sensor to measure the glycerine aqueous solution with different RI, results indicate that the RI sensitivity of the sensor is 159 nm/RIU in the ambient RI range of 1.33 RIU～1. 38 RIU. The fiber sensor has advantages of low-cost, simple mechanism, easy fabrication, high sensitivity, anti-electromagnetic interference, etc. It has great application potentiality in fields of bio-chemical measurement and environmental monitoring.

关 键 词：光纤传感器 折射率 马赫泽德干涉仪 

分 类 号：TN253[电子电信—物理电子学]