Sampled fiber Bragg grating for simultaneous refractive-index and temperature measurement

We present a novel scheme for simultaneous measurement of temperature and r efractive index by use of a single sampled fiber Bragg grating (SFBG). The intrinsic nature of a SFBG that possesses both fiber Bragg grating and long -period grating spectral responses permits the temperature effect to the me asured solely from the former, whereas the refractive-index information is extracted from the latter. Using such a dual-parameter sensor, we successfu lly demonstrated measurement of the dependence on temperature of the refrac tive index of an aqueous solution of sucrose. (C) 2001 Optical Society of A merica.