Integrated Dynamic Wavelength Division Multiplexed FBG Sensors Interrogator on a Silicon Photonic Chip

A wavelength division multiplexed fiber Bragg grating (FBG) sensor interrogator using an integrated unbalanced Mach–Zehnder interferometer followed by an arrayed waveguide grating on silicon-on-insulator platform is presented. The Bragg wavelength shift is determined through the phase-generated carrier demodulation technique, allowing accurate dynamic FBG interrogation. The performance of the proposed device was validated by comparing the measurements with a commercial FBG readout unit based on a spectrometer, serving as a reference. Experimental results demonstrate a dynamic strain resolution of 4.56 nϵ/√Hz and minimum detectable strain down to ∼0.49 μ ϵ at 1-kHz bandwidth.