飞秒激光制备的高灵敏度气压探针传感器

High sensitivity gas-pressure probe sensor fabricated by femtosecond laser

提出并实验验证了一款基于法布里—珀罗干涉仪(FPI)的气压探针传感器。首先将毛细石英管与单模光纤拼接,然后利用飞秒激光将毛细石英管精确切割到极短长度,最后在毛细石英管的端面涂覆聚乙烯醇(PVA)薄膜构成气压传感探针。传感头总长度仅为50μm,可以在有限的空间和恶劣的环境中灵活使用。实验结果表明解调传感器反射谱波长漂移量实现了环境气压测量,气压灵敏度达到-4.457 nm/MPa,线性度为99.52%,气压测量范围0~0.5 MPa。在低温时传感器对温度有一定的依赖性;在高温时传感器对温度不敏感,可以忽略温度对气压测量的串扰。该传感器结构紧凑、灵敏度高、结构重复性好、温度串扰小,在工程实际中具有一定的应用前景。

A gas-pressure sensor based on Fabry-Perot interferometer(FPI)is proposed and experimentally verified to meet the requirements of gas pressure measurement in industrial production.First,the capillary quartz tube is spliced into a single mode fiber.Then,the capillary quartz tube is accurately cut to a very short length by femtosecond laser.Finally,the polyvinyl alcohol(PVA)film is coated on the end face of the capillary quartz tube to form a gas pressure sensing probe.The total length of the sensing head is only 50μm,which can be used flexibly in limited space and harsh environments.The experimental results show that the sensor can measure the gas pressure of the environment by demodulating the wavelength drift of the reflection spectrum.The gas pressure sensitivity is-4.457 nm/MPa,the linearity is 99.52%and the gas pressure measurement range is 0~0.5 MPa.There is a certain dependence on low temperature for the sensor.While,at high temperature,the sensor is not sensitive and the crosstalk between temperature and gas pressure measurement can be ignored.The sensor has compact structure,high sensitivity,good structure repeatability and small temperature crosstalk,which has a certain application prospect in engineering practice.