title: Enhancing the sensitivity of poly(methyl methacrylate) based optical fiber Bragg grating temperature sensors.
abstract: In poly(methyl methacrylate) (PMMA)-based optical fiber gratings (POFBGs), the temperature response is determined by thermal expansion and the thermo-optic effect of the fiber. Because thermal expansion introduces a positive change and the thermo-optic effect introduces a negative change in the Bragg wavelength of the POFBG, they cancel out each other to some extent, leading to reduced and varying temperature sensitivity. By pre-straining a POFBG, the contribution of thermal expansion can be removed, and, consequently, the temperature sensitivity of POFBG can be greatly enhanced. Theoretical analysis also indicates a reduced thermo-optic coefficient of POFBG due to restrained linear expansion that matches experimental results.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: David J
authors.initials: DJ
authors.lastname: Webb
authors.forename: Gang-Ding
authors.initials: GD
authors.lastname: Peng