Comparative Analysis of Horizontal and Vertical Etched Fiber Bragg Sensor for Refractive Index Sensing

Abstract

Etching of Fiber Bragg Grating (FBG) section is necessary process to make the FBG sensitive with the external environment changes. Hence, HF solution is used for this purpose. In the present work, a real time monitoring based system for the vertical and horizontal etching of Fiber Bragg Grating (FBG) in a solution of hydrofluoric (HF) acid is designed. In our experiment we used 40% concentrated HF solution at room temperature, which is corrosive in nature and it capable for dissolving different materials. Because of its reactive nature with glass, we used Teflon container to carry out HF solution. It is easy to analyze the results through the variation of the shifting of wavelength with respect to the etching time response of FBG for horizontal and vertical etching process when dipped in HF solution. The result shows the comparison between vertical etching and the horizontal etching process.