A new setup to tune the center wavelength of FBGs

A novel opening loop structure of fiber Bragg grating is proposed.From the analysis of the strain distribution at the side of the opening loop we found that the structure can be used as a new setup to linearly tune the central wavelength of the fiber Bragg gating.The setup is an uniform fiber Bragg grating bonded to the side of a beam which can produce an uniform strain.The experimental results show that the wavelength range of linear tuning is about 5.0 nm,the sensitivity is about 3.18 nm/N and the linearity is up to 0.998 8.The largest tuning range of the setup is about 11.0 nm while the linearity is 0.994 1 in the range of 0 and 11.0 nm.Experimental results are in good agreement with our theoretical analysis.