Optical Fiber NOX gas Sensor for based on long period fiber grating

• Main Authors: Jui-yi Hsu, 許瑞驛
• Other Authors: Chia-Chin Chiang
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/3m43e7

碩士 === 國立高雄應用科技大學 === 機械與精密工程研究所 === 102 === In this thesis, notched long period fiber grating applicated was applied on NOx gas sensing. By designing different sensor's grating period, fiber daimeter, etching depth, notched long period fiber grating sensor‘s wavelength and transmission characteristic can be obtained. The paper referred to the use of nitrogen oxides WO3 thin film layer (NOX) gas sensing. Notched long period fiber grating (NLPFG) is fabricated by inductive couple plasma etcher. The tensile test observed that notched long period fiber grating sensor’s wavelength will red shift, when fiber diameter is decrease or the grating period is increased. This article WO3 as NOX gas sensing layer and using corona technology hydrophilic surface modification, allowing easier sensing layer coated on the surface of the grating structures.The fiber diameter of 50 μm and Etch depth 11.5 μm have a transmission loss of 2.94 dB. The fiber diameter of 50 μm and Etch depth 16.1 μm have a transmission loss of 3.88 dB .Experiments can be measured oxides (NOX) concentration of 200 ppm and the transmission loss is 1.07 dB.