Temperature Sensor Based on Multimode Fiber Bragg Grating

Abstract

A multimode fiber Bragg grating (MMFBG) is experimentally demonstrated in this paper. The light from the lead-in optical fiber is transmitted to the MMFBG, Bragg gratings in multimode fibers show multiple reflection peaks due to the coupling between all bounded modes. Some reflection peaks are reflected back to the lead-out fiber core by the MMFBG. Finally, the spatial frequency spectra of the reflection peaks are detected by the detection device. As the temperature change, the shifts of the spatial frequency spectrum will be observed. Experimental results show that the MMFBG responds to temperature and the valve of temperature sensitivity is 0.0114 nm/°C. The MMFBG features the advantages of anti-electromagnetic interference, compact structure and stable chemical property, and it exhibits great potential in temperature measurement.