Sensing characteristics of tapered fiber grating

The sensing properties of tapered fiber grating (TFG) are theoretically analyzed. The influence of stress and temperature on characteristics of TFG reflection spectra of different taper angles is analyzed based on transfer matrix method. Results show that the center wavelength shifts to long wavelength and the reflection bandwidth is broadened with increasing of stress. The center wavelength and reflection bandwidth are all linear with the applied stress. The greater the taper angle is, the higher the stress sensitivity of center wavelength and reflection bandwidth will be. The center wavelength shifts to long wavelength when the temperature rises gradually, and the reflection bandwidth is constant. The center wavelength and reflection bandwidth are unchanged when the taper degree increases. The reflection bandwidth of TFG is temperature independent, and only dependent on stress, which can be used to solve the cross-sensitivity problem of temperature and stress.