Cryogenic temperature characteristics of the fiber Bragg grating sensors

The fiber Bragg grating (FBG) sensors have been well studied and used to monitor strain, temperature, or damage in engineering structures which were serviced at ambient temperatures. In order to monitor structure responses which were operated at cryogenic environments, the strain and temperature performance of fiber Bragg grating (FBG) sensors were studied in the temperature range of 123–273 K by three FBG experiments. The temperature sensitive coefficient, strain sensitive coefficient and cross-sensitivity coefficient were derived analytically and verified by experiments. The relationship between the wavelength shift and temperature could be characterized by three-order polynomial. The wavelength shift was linear with the longitudinal strain. Cross sensitivity increased with lower temperature.

► The strain and temperature performance of fiber Bragg grating sensors are studied in the temperature range of 123–273 K.
► The relationship between the wavelength shift and temperature can be characterized by three-order polynomial.
► Strain response is linear with the longitudinal strain at constant temperature.
► The strain sensitivity is stable and temperature-dependent, increasing with decreasing temperature.
► Cross sensitivity increases with lower temperature.