A multiplexing technique for fibre Bragg grating sensors with the same reflection wavelength by the synthesis of optical coherence function

We propose a technique for multiplexing fibre Bragg grating (FBG) sensors with the same Bragg wavelength. We have already developed a technique for the synthesis of an optical coherence function, in which we can select one signal among various reflections along an optical path in an interferometer. By applying the technique, the reflection spectrum of each FBG in arrayed FBGs can selectively be obtained, even if the array is composed of FBGs with the same Bragg wavelength. In this paper, we first describe the principle of the proposed system, and then show the experimental results.