Integrated optical fiber shape sensor modules based on twisted multicore fiber grating arrays

In this paper we report on the development of a complete integrated optical fiber assembly suitable for shape sensing. Our shape sensor module consists of a length (>1m) of twisted multicore optical fiber with fiber Bragg gratings inscribed along its length. Our fiber has a compact 180 micron coated diameter, a twist of 50 turns per meter and grating reflectivities greater than 0.01% per cm of array, suitable for high efficiency scatter measurements over many meters of fiber. Single core to multicore fanouts and low reflectivity fiber termination are used to terminate the end of the array.