Multiplexed LPG sensor system using an InGaAs CCD linear array and optical switches

In this paper we report our progress on the development of a spatially and spectrally multiplexed LPG-based fiber-optic sensor that uses an InGaAs CCD linear array and a diffraction grating for the detection of spectral changes. Three 1×2 fiber-optical switches are used to realize a system of spatial multiplexing of four sensing channels. Up to three LPGs can be connected in series in each channel covering a spectral range from 1525 nm to 1610 nm. The gratings are interrogated in a reflective mode using a tunable fiber reflector and a circulator. The system's performance was tested using bending and mechanical deformations on the gratings.