Active wavelength demodulation of a Bragg grating fibre optic strain sensor using a quantum well electroabsorption filtering detector

The first demodulation of a Bragg grating fibre optic sensor using a semiconductor quantum well electroabsorption device as a filtering detector is reported. The tunable wavelength response of an InGaAs/InP quantum well filtering detector was used in an active manner to track the wavelength of reflected signals from an intracore Bragg grating sensor. A wavelength resolution of ±9.65 pm was achieved with a Bragg grating fibre optic strain sensor operating at ~1535 nm, corresponding to a strain resolution of ±8.04 με