Carbon Nanotube-Deposited Tilted Fiber Bragg Grating for Refractive Index and Temperature Sensing

A tilted fiber Bragg grating (TFBG) deposited with carbon nanotube (CNT) is proposed to simultaneously measure the surrounding refractive index (SRI) and temperature. Assisted by the interaction between the CNT deposition layer and the TFBG's cladding mode, the increase in SRI could significantly attenuate the coupling intensity of cladding modes, while the resonant wavelengths keep almost unchanged. Therefore, the temperature response of the CNT-deposited TFBG could be further obtained by tracking the shifted resonant wavelength. In addition, the CNT deposition greatly enhances the sensing capability in a low refractive index region of 1~1.428 , presenting great potentials in biochemical sensing.