Development of fiber Bragg grating filter based on axial compression technique

A compact Bragg grating filter with a widely tuning range was demonstrated.The filter may be continuously tuned in spectral range of 25 nm by applying the axial compression on the fiber Bragg grating (FBG)which is guided with two special ferrules.Experimental results show that,the Bragg wavelength of the FBG changes linearly with the axial compression displacement.Variations of the reflectivity and 3 dB bandwidth of the FBG are respectively less than 0.59 dB and 0.1 nm during the tuning process.The tunable filter is stable and the Bragg wavelength shift in 30 min is less than 0.07 nm.