Fig. 1. (a) Setup for measuring output spectrum of ultra-broadband light source based on BEDF; (b) fiber Bragg grating (FBG) sensing system with ultra-broadband light source based on BEDF

Fig. 2. Output spectral characteristics of ultra-broadband light source based on BEDF when 830 nm LD used as pump. (a) Output spectrum; (b) variation of relative total emission power with pump power; (c) stability of output spectrum at each peak wavelength; (d) standard deviation of the whole output spectrum

Fig. 3. Transmission spectra by means of output spectra of ultra-broadband light source based on BEDF. (a) FBG1; (b) FBG2 ; (c) FBG3; (d) FBG4; (e) series connection of FBG1, FBG2, FBG3 and FBG4

Fig. 4. Strain sensing based on WDM-FBG. (a) Only FBG2 loading microstrain; (b) only FBG4 loading microstrain