一种新型的液晶填充SM-NC-SM结构光纤温度传感器  

A novel fiber temperature sensor with liquid-crystal filled SM-NCSM structure

作　　者：雷雪琴[1,2] 于雅婷[1,2] 俸闻婧 彭保进[1,2] 李晓东[1,2] 

机构地区：[1]浙江师范大学信息光学研究所,浙江省光信息检测与显示技术研究重点实验室,浙江金华321004 [2]浙江师范大学与浙江大学光学联合研究实验室,浙江杭州310058

出　　处：《光电子．激光》2015年第12期2278-2282,共5页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(61007029;11274278);浙江省自然科学基金(Y15F050012)资助项目

摘　　要：基于向列相液晶（NLC）和多模干涉原理,提出了一种新型的全光纤温度传感器。在两段普通单模光纤（SMF）中间熔接一段直径为200μm、长约为10cm的无心光纤（NCF）,之后将其插入充满液晶的毛细管中并用胶棒密封,实现液晶封装的SM-NC-SM结构的制作。其中,液晶可视为NCF的包层,基于NLC的温度-折射率可调性和热光系数大的特性,能通过SM-NC-SM结构传播的光受到温度调制,通过检测特征波长的漂移实现外环境温度测量。实验测得在27~67℃温度范围内的灵敏度高达626.6pm/℃,并得到特征波长漂移与温度良好的线性关系,其线性度为99.23%。利用设计的传感器搭建了实用的光电检测系统,将波长漂移量的检测转换成电压大小的测量,测得相对误差小于4%。本文设计的传感器结构简单、成本低和灵敏度高,为温度传感应用提供了一种新方法。Based on nematic liquid crystal （NLC） and multimode interference principle, a novel all-fiber temperature sensor is proposed. A piece of no-core fiber （NCF） with a large diameter of 200μm and 10 cm in length is spliced between two single-mode fibers to form a single mode （SM）-no core （NC）-SM structure. As the micro-structure is sealed in an NLC-filled capillary with glue, the compact temperature sensing probe is fabricated. The liquid crystal can be considered as the cladding of NC fiber. Based on the extraordinarily large thermo-optic coefficient （dn/dT） of NLC and tunable refractive index of NLC with the temperature,the light which can pass through the SM-NC-SM structure is modulated by temperature. And by measuring the wavelength shift of the peak, the environmental temperature detection can be achieved with the high sensitivity of 626.6 pm/℃ in a temperature range of 27-67℃. We have also built the corresponding photoelectric system to convert the detection of wavelength shifts into the voltage size measurement,and the relative error is less than 4%. Given the nature of simplicity, low cost and high sensitivity,the presented fiber sensor with NLC-filled SM-NC-SM structure provides the potential to temperature sensing applications.

关 键 词：液晶 无心光纤(NCF) 多模干涉 光纤传感器 温度传感器 

分 类 号：TN253[电子电信—物理电子学]