基于双金属结构的光纤光栅温度不敏感滤波器  

Fiber Bragg grating temperature insensitive filter based on bimetal structure

作　　者：廖晶晶 祝连庆[2,3] 宋言明[1,3] 辛璟焘[1,2] 吕峥 Liao Jingjing;Zhu Lianqing;Song Yanming;Xin Jingtao;Lv Zheng(Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument,Beijing Information Science&Technology University,Beijing 100192,China;Beijing Laboratory of Optical Fiber Sensing and System,Beijing Information Science&Technology University,Beijing 100016,China;Beijing Key Laboratory of Optoelectronic Measurement Technology,Beijing Information Science&Technology University,Beijing 100192,China)

机构地区：[1]北京信息科技大学光电测试技术及仪器教育部重点实验室,北京100192 [2]北京信息科技大学光纤传感与系统北京实验室,北京100016 [3]北京信息科技大学北京市光电测试技术重点实验室,北京100192

出　　处：《红外与激光工程》2023年第3期314-321,共8页Infrared and Laser Engineering

基　　金：北京市自然基金-市教委联合基金项目(KZ201911232044)。

摘　　要：为提高光纤陀螺宽谱光源的平均波长稳定性,提出了一种用60μm超短光纤光栅制作带宽11.77 nm温度不敏感滤波器的方法。利用金属材料的热膨胀系数差,设计了双金属温度补偿结构,能够随温度的升高/降低对光纤光栅压缩/拉伸,有效地补偿光纤光栅由热光效应引起的波长变化。在30~60℃的温度范围内,光纤光栅的温度灵敏度系数为0.15 pm/℃,较未补偿前降低了60倍以上。该结构具有较好的温度不敏感性,可作为光源滤波器提高光源的平均波长稳定性并有望用于高精度光纤陀螺。Objective Fiber optic gyroscopes(FOG)are a new class of instrument capable of accurately determining the orientation of moving objects,which have been widely used in tactical missile guidance,land traffic navigation and aerospace attitude adjustment because of their long service life,easy integration and small size,etc.However,the changing operating temperature in these application fields seriously reduces the average wavelength stability of the broad spectrum light source in the fiber optic gyroscope,thus hindering the further application of the fiber optic gyroscope.To improve the average wavelength stability of the fiber optic gyro wide spectrum light source,this study proposes a method to make a temperature-insensitive filter with a bandwidth of 11.77 nm using a 60μm ultrashort fiber grating.Methods The bimetallic temperature compensation structure(Fig.1)is designed based on the thermal expansion coefficient difference between two metal materials.This structure will compress/stretch the fiber grating with the increase/decrease of temperature and effectively compensate for the wavelength change of fiber grating caused by the thermo-optic effect.The filter is fabricated by combining metal material with fiber grating in two-point packaging,and the effects of the thermal expansion coefficient of the material and the geometric parameters of the filter on the temperature sensitivity of the filter are systematically studied.Results and Discussions The results show that the temperature sensitivity of the filter is mainly affected by the thermal expansion coefficient and length of the substrate and the strain transfer beam.The largest adjustable range of L_(1)/L_(2)(the ratio of the length between two fixed points on the substrate and the length of the filter fiber grating)is achieved as the thermal expansion coefficient difference is−5.8.Besides,the temperature sensitivity of the filter exhibits a negative linear relationship with the value of L_(1)/L_(2).According to the comparison of the control variable method,

关 键 词：光纤陀螺光源 光纤光栅滤波器 双金属结构 温度补偿 

分 类 号：TN253[电子电信—物理电子学]