Very high sensor-density multiplexing using a wavelength-to-time domain reflectometry approach based on a rapidly swept akinetic laser

We demonstrate a scheme for the interrogation of arrays of FBG sensors based on a Swept Laser Distributed Sensing system which can achieve 1000 sensors or more in a single fiber, while retaining the sensitivity and repeatability expected with FBG sensors of better than 0.5 μepsilon and 0.05 C. The system utilizes an ‘akinetic’ wavelength swept source and an arrival time-dependent detection approach to allow potentially 1000s of very low reflectivity FBGs to be monitored via a form of Wavelength-to-Time Domain Reflectometry. We demonstrate the interrogation of 250 gratings in a system architecture designed to support 1000 gratings.