Open AccessStrain, bending, refractive index independent temperature sensor based on a graded index multimode fiber embedded long period fiber grating
Author(s) -
Huiwen Niu,
Wenhuan Chen,
Yue Liu,
Xiren Jin,
Xiang Li,
Feng Peng,
Tao Geng,
Shuo Zhang,
Weimin Sun
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.430168
Subject(s) - materials science , optics , multi mode optical fiber , long period fiber grating , refractive index , fiber bragg grating , fiber optic sensor , graded index fiber , optical fiber , normalized frequency (unit) , bending , grating , wavelength , fiber , optoelectronics , physics , composite material , phase locked loop , frequency synthesizer , phase noise
A novel embedded ultra-long period fiber grating (EULPFG) based on a graded index multimode fiber (GI-MMF) is proposed for temperature measurement. Due to the small RI difference of the modes near the GI-MMF self-imaging point, the resonant peak of transmission spectrum is wavelength-insensitive to refractive index (RI), strain and bending. However, the sensor is sensitive to temperature. The experimental results show that the temperature sensitivity of the EULPFG is 90.77 pm/°C. The sensitivities of other physical parameters are suppressed, and the suppressed sensitivities are at least one order of magnitude less than those of similar sensors. The EULPFG with anti-interference from other parameters is expected to be used in ocean monitoring systems to measure the temperature of the seawater.