Alcohol Filled Side-Hole Fiber Tilted Fiber Bragg Grating for Temperature Measurements

Abstract

A compact temperature sensing element based on tilted fiber Bragg grating (TFBG) is filed with an alcohol and written in side-hole fiber. The sensing element is first proposed and experimentally demonstrated. The tilted fiber Bragg grating is written in side hole fiber. The transmission spectrum of TFBG sensor has two resonant dips. The wavelengths are sensitive to the change of refractive index of the traditional alcohol filled side-hole fiber. Experimental results show a high temperature sensitivity reaches to 15 pm/ °C for 10 mm TFBG length written in 7cm-long side hole fiber used which about 1.5 times higher than that of FBG sensing element.