基于表面等离子体共振效应的单模光纤高灵敏度温湿度传感器

Abstract

Objective Accurate measurement of temperature and relative humidity plays an important role in many fields, such as health care, environmental testing, and safety monitoring. Various sensor devices have been developed to meet various needs, but traditional mechanical hygrometers and thermometers, as well as temperature and humidity sensors based on capacitance and resistance, have disadvantages, such as large space occupation and deterioration from aging. Fiber sensors have become a popular research topic because of their small size, light weight, resistance to electromagnetic interference, corrosion resistance, and many other advantages.Researchers have designed optical fiber temperature and humidity sensors that use grating structures, interference structures, and surface plasmon resonance (SPR) effects by combining optical fibers with temperatureand humiditysensitive materials. The SPR effect has attracted considerable attention because it improves the sensitivity of optical fibers in sensing the change in the refractive index of the surrounding medium. We propose an SPRbased singlemode fiber (SMF) temperatureand humiditysensing structure.It is made of a singlemode fiber coated with a silver film that partially removes cladding and senses the changes in temperature and relative humidity via a sensitive material, which is on the outer side of the silver.