Fig. 1. Schematic of fiber temperature sensor based on RDDFP

Fig. 2. Simulation of RDDFP. (a) Geometric structure design; (b) simulation results of mode filed propagation of core-mode and cladding-mode in the RDDFP; (c) relationship between power of core-mode, power of cladding-mode, and total energy of RDDFP and distance of transmission

Fig. 3. Simulation of relation between interference intensity and interference length L

Fig. 4. Experimental setup of proposed fiber temperature sensor

Fig. 5. Experimental results of interference spectra of EDDFP varying with temperature. (a) Interference spectra measured at different temperatures; (b) relationship between wavelength shift and temperature

Fig. 6. Experimental results of interference spectra of YDDFP varying with temperature. (a) Interference spectra measured at different temperatures; (b) relationship between wavelength shift and temperature

Fig. 7. Experimental results of EDDFP sensor for different L. (a) Interference spectra measured at the same temperature of 25 ℃; (b) temperature sensitivity