Application of Fiber Bragg Gratings for Measuring the Crack Opening Rate

The use of fiber Bragg gratings in the device for measuring the rate of crack opening in various materials under mechanical load is considered. The technical requirements for the structural elements including tunable wavelength semiconductor laser using the Peltier element have been established. The possibility of measuring the crack opening parameters by changing the power of the radiation reflected by the Bragg grating due to change in the resonant wavelength of the grating with time delays of less than a microsecond has been experimentally demonstrated.