基于纺锤型空气腔的光纤马赫-曾德尔折射率传感器

设计了一种基于光纤纺锤型空气腔的三明治结构全光纤马赫-曾德尔折射率传感器。纺锤型空气腔是通过普通单模光纤和光子晶体光纤熔接后再拉锥形成的。锥区的纺锤型空气腔和包层分别作为参考臂和传感臂,从而形成马赫-曾德尔干涉。基于FDTD Solutions和COMSOL仿真软件分别对传感器的干涉条纹及锥区电场分布进行了仿真,得到了折射率传感器干涉条纹波谷波长和有效折射率与环境折射率的关系。当环境折射率为1.36~1.37和1.37~1.38时,灵敏度分别为1 377.6和1 436nm/RIU。此传感器具有极短的干涉臂,能够降低损耗,且具有较高的折射率灵敏度。

Optical Fiber Mach-Zehnder Refractive Index Sensor Based on Spindle Air Cavity

A sandwich-structured all-fiber Mach-Zehnder refractive index sensor based on a spindle-type air cavity was designed. The spindle-type air cavity was manufactured by splicing and taper acommon single-mode optical fiber and a photonic crystal fiber. The spindle-type air cavity and cladding in the taper area serve as the referring and sensing arms respectively, then the Mach-Zehnder interference is established. The interference fringes of the sensor and the electric field distribution in the taper area were simulated respectively based on FDTD Solutions and COMSOL. The relationship between the trough wavelength of the index sensor and the environmental refractive index, the effective refractive index and the environment refractive index are obtained by simulations. The sensitivity is 1377.6 and 1436nm/RIU when the refractive index is 1.36~1.37 and 1.37~1.38 respectively.The extremely short interference arm is used to reduce the loss and the sensor has higher refractive index sensitivity.