A spectrally and spatially multiplexed LPG sensor system using an InGaAs CCD linear array

Abstract

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 1x2 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. The end grating of each channel has a fiber reflector spliced to it and the reflected signals are directed to the detection unit via a circulator. To test the system bending and external refractive index changes have been traced.

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

“…A differential scheme over spectral pass-bands on either side of the LPG minimum for interrogation of spectrally multiplexed LPGs has been studied in [11]. Also, a dynamic differential scheme using modulated FBGs has been implemented to interrogate three in-series [12] and spatially multiplexed [13] LPGs.…”