광반응 재료를 이용한 광섬유 자외선 센서

Abstract

In this thesis, we have demonstrated the azobenzene-coated fiber Bragg grating (FBG) to monitor ultraviolet light (UV) intensity in remote measurement. The elasticity of the coated azobenzene polymer is changed by the UV light, which induces the center wavelength change corresponding to the change of the FBG’s grating period. There are two methods of coating the azobenzene polymer on the FBG. These are the thermal casting method and the UV curing method. Center wavelength shift considered, UV curing method is more suitable for the UV sensors. Also, we have confirmed the center wavelength shift and shift aspect, and found that azo-coated FBG fabricated by using the Teflon casting is more suitable for the UV sensors and easy to supplementation. To confirm the spectral response characteristics of the azo-coated FBG, we measured the magnitude of the center wavelength variation using bandpass filters. Consequently, the amount of the center wavelength variation of the azo-coated FBG is determined by the absorption spectrum of the azobenzene polymer, and the azo-coated FBGs show a superior reaction in shorter wavelength regions. Through this characteristic of the azo-coated FBG, we found the possibility as a UV sensor that can use in the various UV regions. We experiment repeatedly to confirm the reproducibility and reliability, and therefore, the azo-coated FBG shows the superb reproducibility and reliability. Furthermore, we find the new research design through the intensity variation of the resonant wavelength.