提出了一种基于飞秒激光加工的微结构湿度传感器.在光纤布拉格光栅(FBG)包层上用飞秒激光加工直槽微结构,然后涂覆聚酰亚胺湿敏薄膜(PI膜)制成湿度传感探头.文章理论分析了直槽微结构提高传感器性能的工作原理,介绍了传感器探头的制备工艺和性能影响因素,给出了不同直槽个数微结构探头的湿度测试结果.实验结果表明,光栅上加工直槽微结构均能显著提高探头灵敏度.激光能量和镀膜厚度一定时,直槽个数越多,灵敏度越高,最高可达2.55 pm/%,相比无微结构探头,灵敏度提高了2.6倍.%A bstract:A kind of micro-structured humidity sensor based on femtosecond laser processing was proposed.The groove struc-ture was processed in the optical fiber grating cladding by a femtosecond laser,then coated with a polyimide humidity sensing film (PI film)to make it a humidity sensing probe.The principle of improving the sensor performance of groove microstructure was an -alyzed in theory.The fabrication process and factors affecting sensor performance were described.The humidity response results of several probes with different structure were demonstrated.The experimental results show that groove microstructure on the grating can significantly improve the sensitivity of the probe.When laser energy and coating thickness remains unchanged,the more groove number is,the higher the sensitivity is.And the maximum sensitivity can reach to 2.55 pm/%,which is 2.6 times higher than that of non-microstructured probe.
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