Resonant cavity based fibre Bragg grating sensor interrogation using ratiometric detection

Time-division-multiplexing of fibre Bragg gratings using a novel resonant cavity architecture is described. Independent extraction of amplified optical signals from individual sensors is demonstrated, making it possible to use a low-cost, passive wavelength measurement technique for sensor readout. Using a commercial ratiometric filter component, the complete interrogation system remains simple and solid-state. Results show that the configuration has the capability to deliver static measurements with picometre resolution, or to perform vibration analysis at up to 4.4 kHz.