An Experimental Study about Humidity Sensors Based on Tapered Optical Fibers

摘要

A humidity sensor is proposed for detecting air moisture content based on tapered optical fiber. According to optical energy transmission theory, geometrical optics, the sensing mechanism of humidity sensor is described by analyzing the evanescent field around the sensing fiber. The relationships between the dimensions and spectral characteristics of the taper have been analyzed, respectively. The results show that the taper shape is important for designing a humidity sensor. The experimental curves can be obtained by comparing the transimission loss and humidity, and the errors are also given. The humidity is analyzed in different air moisture content. The humidity measurement resolution is 1% as the measuring range varies within 50-95%. The transmision loss decreases as increasing humidity. Thus, the high dynamic performance can allows this sensor to be used for humidity monitoring in time.