Research On Cross-Sensitivity Of Stress And Temperature In Fiber Bragg Grating Temperature Sensor

With the characteristics of small sensing unit,high sensitivity,to avoid interference from electromagnetic waves,easy to multi-point monitoring,fiber grating sensors are widely used in many sensing areas.People obtain great economic benefits and a safe and convenient way of life.The features of the tapered fiber Bragg grating can be a good solution to temperature and stress crosssensitive issues.In this paper,through the establishment of mathematical model,and combined with the transmission matrix method,the axial strain and temperature sensing characteristics of the linear tapered fiber Bragg grating is simulated.Then,a tapered fiber Bragg grating with parabolic surface is proposed,and the same grating parameters are used to compare the two gratings.The results show that the reflection bandwidth of the two kinds of tapered fiber gratings is dependent on the stress but independent on the temperature.The reflection bandwidth and the central wavelength of the linear tapered fiber grating are linearly related to the stress,while the reflection bandwidth of the parabolic fiber grating are non-linear relationship with the stress.The temperature sensing characteristics of the two fiber grating are consistent,indicating that changing the external structure of the fiber does not affect the temperature sensitivity.Finally,the tapered fiber grating is fabricated by arc discharge technology,and its axial strain and temperature sensing characteristics are studied.The strain sensitivity and temperature sensitivity are 0.9468)/ and 0.0118nm/?,respectively.The characteristics show that there is a transmission peak in the reflection spectrum,and the distance between the center wavelength of the transmission peak and the edge of the reflection spectrum is not affected by the temperature.However,with the increase of the axial stress,the center wavelength of the transmission peak gradually changes to the long wavelength direction to move.