Characterization and calibration of shape sensors based on multicore optical fibre

[EN] In order to provide high accuracy in shape measurement with multicore optical fibres, characterization and calibration procedures are an important part of sensor preparation. Some procedures can be considered mandatory for adequate shape reconstruction, while others can help to enhance the measurement accuracy. Several of such procedures are discussed and experimentally applied for demonstrating the possible performance enhancement of curvature sensing, a fundamental phase of the shape reconstruction process. The maximum error observed in curvature calculation for a test object has been proved to be almost halved, decreasing from 2.48% to 1.36%, by applying such calibration corrections. The overall average relative accuracy of curvature measurement was improved from 0.89% to 0.5% (an improvement of 44%).