基于微椭球空气腔的光纤压力传感器的设计

A Design of Optic Fiber Pressure Sensor Based on Micro In-Fiber Ellipsoidal Cavity

摘要:

设计了一种新型的在线光纤法布里-珀罗(F-P)压力传感器。该传感器的F-P腔为微椭球空气腔,由光纤熔接机以特定的熔接参数熔接单模光纤和实芯光子晶体光纤而成。该传感器基于F-P干涉原理测量压力,全石英结构,制作工艺简单,温度串扰小。分析了封闭的椭球形空气F-P腔中短轴直径(腔长)与长轴半径(敏感膜有效半径)的关系;利用高斯光束传输理论分析了空气F-P腔形状与腔内损耗的关系。分析了SiO2敏感膜受压后中心挠度与膜厚、有效半径的关系。建立了SiO2膜的压力敏感特性模型,在施加均布载荷条件下对模型的挠度形变特性进行了数值解析和有限元仿真。仿真了传感器F-P干涉条纹波谷波长与压力的关系,为设计制作光纤微压传感器提供了理论依据。

Abstract:

A new type of on-line fiber Fabry-Perot (F-P) pressure sensor was proposed. The F-P cavity of the sensor is a micro-ellipsoidal air cavity, which is formed by splicing together a SMF and a solid-core PCF with the specific splicing parameters. The pressure sensor based on F-P interference principle has many advantages such as all-silica structure, simple production process and small temperature cross-talk. In this paper, the relationship between the diameter of the short axis (cavity length) and the radius of the major axis (the effective radius of the sensitive film) in the sealed ellipsoidal air F-P cavity was analyzed. The relationship between the shape of the air F-P cavity and the cavity loss was analyzed by Gaussian beam transmission theory. The relationship among the center deflection, the film thickness and the effective radius of the SiO2 sensitive membrane was analyzed. The pressure sensitive characteristic model of SiO2 film was established, and the numerical analysis and finite element simulation were carried out under the condition of uniform load. The relationship between the wavelength and the pressure was simulated, and it provided a theoretical basis for the design of optical fiber micro-pressure sensor.