Continuous Multicore Optical Fiber Grating Arrays for Distributed Sensing Applications

We describe the fabrication and distributed sensing capabilities of very long continuous fiber grating sensor arrays in a twisted multicore fiber. The continuous gratings are fabricated in fibers with UV transparent coating using a flexible and scalable reel-to-reel processing system. Single-frequency continuous gratings are characterized using optical frequency-domain reflectometry and a shape reconstruction algorithm to measure fiber bend radius. Broadband reflection gratings are shown to act as enhanced quasi-Rayleigh scattering elements allowing for distributed temperature measurements in the presence of 10-dB transmission loss.