摘要
提出了一种基于马赫-曾德干涉仪(MZI)的温度与折射率同步测量的光纤传感器。本文传感器结构由两个球形结构级联一个锥结构组成,球形结构激发高阶包层模,锥结构扩大了倏逝场穿透深度范围。其原理是当纤芯中传输的光通过第1个球形结构时,一部分光进入包层中传输形成包层模,另一部分光继续在纤芯中传输形成纤芯模,由于纤芯与包层具有不同的折射率,因而纤芯模和包层模之间产生光程差,当两部分光到达另一端的球形结构时,在包层中传输的光耦合进入纤芯,从而与纤芯中传输的光在另一球出射处发生干涉,当外界环境(如温度、折射率等)发生改变,影响光程差,则干涉谱也将随之改变。实验结果表明,本文传感器结构的透射谱中,干涉峰对温度和折射率具有不同的响应灵敏度,因此可以利用矩阵法实现对温度和折射率的同步测量。在10~100℃和1.343 2~1.402 6RIU(refractive index unity)的测量范围内,强度解调可以达到约0.22℃和1×10^(-4) RIU温度和折射率分辨率。同时发现,波长解调可以达到0.37℃温度分辨率。本文传感器结构简单紧凑、成本低,可适用于多领域实现温度和折射率的双参量同步测量。
An optical fiber sensor based on Mach-Zehnder interferometer （MZI） is proposed and experi- mentally demonstrated for the measurement of temperature and refractive index simultaneously. It is composed of a pair of spherical-shape structures and an embedded taper, where the spherical-shape structure excites high-order cladding modes,and the taper enhances the penetration depth range of eva- nescent field. When the light launching in the core encounters spherical-shape 1, part of light is excited into cladding forming cladding modes, while other light continues transmitting in the core forming funda- mental mode. The fundamental mode and cladding modes have optical path difference because of different refractive indices. And the cladding modes could recouple with the fundamental mode and interfere at the spherical-shape 2. Experimental restdts show that the interference peaks of the transmission spectrum have different sensitivities to temperature and refractive index, so that a matrix can be used to achieve the simultaneous measurement of the temperature and refractive inde Within the range of 10-100 ℃ and 1. 343 2--1. 402 6RIU,temperature resolution and refractive index resolution of 0.22℃and 1 X 10-4 RIU can be achieved by intensity-modulation. We also find that the temperature resolution is 0. 37 ＊C by wavelegth-modulation.
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2017年第2期123-127,共5页
Journal of Optoelectronics·Laser
基金
国家自然科学基金(11404310)
浙江省自然科学基金(LY13F050004)资助项目
关键词
光纤传感器
马赫一曾德干涉仪(MZI)
同步测量
温度
折射率
optical fiber sensor
Mach-Zehnder interferometer （MZI）
simultaneous measurement
tem-perature
refractive index
