Analysis and Development of a Tunable Fiber Bragg Grating Filter Based on Axial Tension/Compression

A tunable optical filter based on the axial strain of the fiber Bragg grating (FBG) is discussed. A wavelength range of 46 nm in compression and 10.5 nm in tension with negligible variations in reflectivity and bandwidth of the central Bragg wavelength reflectivity peak were obtained. The device consists of two fixed ferrules and one guiding ferrule. The difficulties with compressing the FBG were handled by carefully selecting tolerances and adjustment procedures. The device allows both tension and compression of FBG and the use of different FBG lengths and actuators. The effects of glue deformation and bending of the FBG during compression are analyzed in detail.