基于螺旋形纤芯的长周期光纤光栅扭转传感器  

Torsion Sensor Based on Helical-Core Long-Period Fiber Grating

作　　者：马一巍 田甜 耿涛 苑立波 Ma Yiwei;Tian Tian;Geng Tao;Yuan Libo(Key Laboratory of In-Fiber Integrated Optics,Ministry of Education,Harbin Engineering University,Harbin 150001,Heilongjiang,China;College of Materials Science and Chemical Engineering,Harbin Engineering University,Harbin 150001,Heilongjiang,China;Photonics Research Center,Guilin University of Electronic Technology,Guilin 541004,Guangxi,China)

机构地区：[1]哈尔滨工程大学纤维集成光学教育部重点实验室,黑龙江哈尔滨150001 [2]哈尔滨工程大学材料科学与化学工程学院,黑龙江哈尔滨150001 [3]桂林电子科技大学光子学研究中心,广西桂林541004

出　　处：《光学学报》2024年第11期258-264,共7页Acta Optica Sinica

基　　金：黑龙江省重点研发计划(GA23A909)。

摘　　要：提出并制备了一种基于螺旋形纤芯的长周期光纤光栅扭转传感器。首先利用激光器对单模光纤进行周期性的多面蚀刻,然后对加工完成的光纤结构进行熔融加热,在表面张力的作用下,结构表面的凹槽形状可以转化为内部纤芯的变形。当该传感器受到外界施加的扭转时,其纤芯的螺旋状态会被改变,从而使得结构纤芯和包层的有效折射率发生改变,达到提升传感器扭转灵敏度的目的。实验结果表明螺旋芯长周期光纤光栅在-18.42 rad/m至18.42 rad/m的测量范围内的扭转灵敏度可以达到0.37 nm/(rad/m),同时该传感器具有1.75 mm的紧凑长度。Objective Torsion is one of the most important physical parameters in industrial automation control and robotics.Optical fiber sensors feature small size,light weight,and electromagnetic interference resistance,providing reliable measurement results under such extreme working scenarios as flammable and explosive,high temperature,high pressure,and strong electromagnetic properties.Among them,long-period fiber grating(LPFG)shows superiority due to the high sensing sensitivity,low transmission loss,directional judgment,and mature of preparation method.However,the sensitivity and length of LPFGs limit the applications in extremely special environments,such as industrial automatic control and intelligent robots.Thus,we aim to enhance the sensitivity and shorten the length of the LPFGs by simulation analysis and experimental optimization.Meanwhile,a new method for fabricating LPFGs is proposed and the sensing mechanism of the torsion sensors is also investigated.Finally,we hope our study can provide some ideas for the design of optical fiber torsion sensors.Methods We experimentally propose and theoretically study a torsional sensor based on helical-core LPFGs.The fabricating steps for the structure are as follows.Firstly,a high-frequency CO2 laser is employed to periodically etch the single-mode fiber to form a preheated structure,and then the fiber-preheated structure is heated.Meanwhile,the grooves of the preheated structure are transformed into the core deformation under the surface tension of the molten glass.When the sensor is subjected to external torsion,the helical state of the fiber core is changed to alter the effective refractive index of the core and cladding to improve the torsional sensitivity of the sensor.Results and Discussions The light distribution of the proposed fiber sensor is theoretically analyzed and simulated.When the incident light passes through the helical-core structure,the energy decreases rapidly within 0.8 mm.With the increasing propagation distance,most of the light propagating in the

关 键 词：光纤光学 光纤传感器 长周期光纤光栅 螺旋纤芯 扭转 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]