Enhanced pressure and temperature sensitivity of a fiber Bragg grating with polymer packaging

We demonstrate the higher pressure and temperature sensitivity of a fiber Bragg grating (FBG) sensor when it is packaged with a polymer jacket. The Bragg wavelength shift due to pressure and temperature can be enhanced by the polymer packaged by about 31.5 times for pressure and 7.7 times for temperature. The experiment results are consistent with the theoretical analysis. The sensitivity enhancement is due to the driving effect of the polymer substance. The 'structured' grating exhibits no significant chirp.