飞秒激光加工光纤法布里-珀罗温度传感器微槽实验研究(特邀)  

Experimental study on microgrooves of optical fiber Fabry-Perot temperature sensor processed by femtosecond laser(invited)

作　　者：尹泽坤 陈伟康 谢合瑞 崔健磊[1] YIN Zekun;CHEN Weikang;XIE Herui;CUI Jianlei(State Key Laboratory of Mechanical Manufacturing Systems Engineering,Xi'an Jiaotong University,Xi'an 710049,China;Xi’an Space Engine Co.Led.,Xi’an 710061,China)

机构地区：[1]西安交通大学机械制造系统工程国家重点实验室,陕西西安710054 [2]西安航天发动机有限公司,陕西西安710061

出　　处：《红外与激光工程》2024年第11期91-101,共11页Infrared and Laser Engineering

基　　金：航空发动机及燃气轮机基础科学中心重大项目(P2022-A-IV-002-003);陕西省重点研发计划项目(2021ZDLGY10-02)。

摘　　要：光纤温度传感器相较于传统光学功能器件具有损耗小、抗电磁干扰能力强、耐腐蚀等优点,其中的光纤法布里-珀罗传感器更因其结构简单紧凑、稳定性好、易于制造受到广泛关注。光纤法布里-珀罗传感器功能结构的传统加工工艺存在工艺复杂、加工效率低下、热影响区严重等问题。光纤作为纤细透明的脆性材料,激光作为非接触的加工方式和微米尺度的聚焦光斑可以有效避免机械性破坏同时可以实现多样性的加工,已经广泛应用于光纤温度传感器的加工。目前,激光加工依然存在纤芯区域粗糙度高、平行度低、加工质量较差等难题。为了确保激光加工的法布里-珀罗腔能够满足传感性能要求,文中进行了飞秒激光加工法布里-珀罗腔的工艺实验研究,得到了不同激光参数、扫描路径对加工法布里-珀罗空气腔的影响规律,发现采用往复式扫描方式并在激光功率选用10 mW、扫描速度100μm/s、扫描间隔4μm、扫描分五次逐次向下进给5μm的工艺参数组合后,可以加工出两反射面接近平行(87.95°),侧壁光滑、面粗糙度稳定在2~4μm的良好形貌法布里-珀罗腔。加工了5种不同腔长的光纤中,腔长为80μm的传感器性能最优为21.07 pm/℃。将腔长为80μm的传感器封装在3种金属管中进行测试,结果证明激光加工光纤法布里-珀罗温度传感器的质量得到了进一步优化,性能进一步提升。但不同的封装材料会较大影响传感器的探测效果,结果发现封装材料的热膨胀系数越大,温度传感器的响应特性越好。Objective Compared to traditional optical devices,fiber optic temperature sensors have the advantages of low loss,strong electromagnetic interference resistance,and corrosion resistance.Fiber optic Fabry-Perot(FP)sensors have attracted widespread attention due to their simple and compact structure,excellent stability,and manufacturing feasibility.However,there are some issues with the conventional methods used to fabricate the functional structures of fiber optic Fabry-Perot sensors,such as intricate fabrication procedures,low processing efficiency,and severe heat-affected zones.As optical fiber is a thin,transparent,and brittle material,laser as a non-contact processing method and micron-scale focused spot can effectively avoid mechanical damage and achieve diverse processing.Currently,challenges in laser processing include high surface roughness in the fiber core area,poor parallelism,and poor processing quality.Therefore,it is necessary to establish a set of laser process parameters that can process fiber Fabry-Perot cavities with high quality to ensure that the processed cavities meet the performance requirements of the sensors.For this purpose,this study conducted experimental research on femtosecond laser processing of FP cavities.Methods This study used a low-repetition-rate infrared femtosecond laser processing system(Fig.1)to conduct experiments on optical fibers and explore the effects of laser parameters on the morphology of the microcavity.The microcavities were observed using a laser confocal microscope and an optical microscope(Fig.2-7),and the roughness of the sidewalls of the processed microcavities was measured(Tab.2).The processed optical fiber is placed in a temperature box,and the response characteristics are obtained using a broadband light source and a spectrometer(Fig.9).Select the optimal cavity length based on the response characteristics,and package the sensor with a cavity length of 80μm in a metal tube for testing,and obtain the response characteristics after packaging(Fig.11)Results

关 键 词：飞秒激光 微槽加工 单模石英光纤 法布里-珀罗腔 温度传感器 

分 类 号：TN249[电子电信—物理电子学]