D型光纤传感器的飞秒激光加工方法  

Femtosecond laser micromachining of D-shape optical fiber sensor

作　　者：邓旺[1] 周剑英[1] 孙小燕[1] 银恺[1] 罗志[1] 谭超[1] 周江夏子 段吉安[1] 

机构地区：[1]中南大学高性能复杂制造国家重点实验室,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2015年第12期4476-4480,共5页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(91123035;51005250);国家重点基础研究发展计划(973计划)项目(2011CB013000)~~

摘　　要：基于飞秒激光加工系统中二维CCD观测定位的轮廓线方法加工D型光纤,研究离焦量对飞秒激光轮廓线加工质量的影响。研究结果表明：随着聚焦光斑焦平面从光纤的近物镜端逐渐深入光纤,D型光纤加工面沿光传播方向的轮廓倾斜度会变得越来越大。飞秒激光加工方法能够保证加工的一致性。加工的D型光纤有效长度为200μm,从包层顶端到加工面的加工深度为56.4μm,原子力显微镜测得纤芯附近加工表面粗糙度为129 nm。将加工好的D型光纤用于折射率为1.36~1.42的液体传感,测得其传输损耗随折射率线性增大,此D型光纤传感器的单位折射率的传感灵敏度为37 d B。本文的加工方法在提高效率的同时,能够保证D型光纤的加工精度及传感灵敏度。A D-shape optical fiber sensor fabricated by profile-line method based on two-dimensional CCD observation in femtosecond laser micromachining system was proposed. Experiments were carried out to research the effect of defocus on the profile-line machining results. The results show that with the focus plane going deep into the fiber from the side close to objective, the profile-line slope of the machined surface of D-shape optical fiber gets larger in the direction of laser propagation. This method can guarantee the machining repeatability. The dimensions of the D-shape zone are 56.4 μm in depth measured from the surface of the cladding, and 200 μm in effective length. The mean roughness of the surface around the fiber core is 129 nm as determined by AFM. The transmission loss of the D-shape optical fiber sensor immersed in liquid increases linearly with its refractive index in the range of 1.36 to 1.42. The calculated sensitivity of the sensor for unit of refractive index is 37 d B. The profile-line method can not only improve the efficiency, but also guarantee the high machining precision and sensing sensitivity.

关 键 词：飞秒激光 D型光纤 轮廓线加工 离焦量 折射率传感 

分 类 号：TN249[电子电信—物理电子学]