Preparation and calibration of the optical sensors with fiber Bragg grating.

We present our research in the field of set-up of fiber sensors with fiber Bragg gratings. We prepared complete technique from the preparation of phase masks, writing FBG into the hydrogen loaded optical fibers, preparation of sensors up to calibration of optical sensors. We present method of measurement of fiber Bragg gratings (FBG) stretching by laser interferometer. The elongation of FBGs can be calculated from frequency drift of the Bragg resonance wavelength and from the change of the grating period during stretching. The inhomogeneity of optical fibers and of the FBGs can induce change of the grating period (Bragg resonance wavelength) of FBG which can be nonlinear with elongation of the optical fiber with FBG. The calibration of FBGs will be used to preparation and to the realization of the technology of measurement of shape deformation of concrete buildings.