Temperature insensitive measurement of bending force with using TFBG sensor

From the beginning of fiber optic sensors development, Fiber Bragg Gratings have been considered as excellent sensing elements, suitable for temperature, strain, force etc. measurement. Tilted Bragg Gratings are made by modification of FBGs by creating a tilt angle between optical fiber axis and refractive index changes plane. It causes a serious differences in properties of this structure against traditional Fiber Bragg Grating. Ability for measuring refractive index of surrounding entourage is most frequently used property of TFBGs. Insensitivity from temperature changes of sensing which is based on resonant modes measurement is a strong advantage against traditional Bragg gratings in which temperature and other measurands causes similar shift of spectrum. In this paper are presented results for bending optical fiber with created TFBG in circular shape with different diameters and placing in different temperatures. Grating processing characteristics with temperature sensitivity are presented.