High accuracy calibration method for 3D curve reconstruction based on a twisted multicore fiber

A high accuracy calibration method for three-dimensional (3D) curve reconstruction based on a twisted multicore fiber (MCF) is proposed and experimentally investigated. The core spacing, core azimuth, and twist bias of the twisted MCF are decoupled and calibrated according to the amplitude, phase, and period information derived from the strain curves. A 3D curve reconstruction experimental system based on the twisted MCF and optical frequency domain reflectometry (OFDR) is established, and the curve reconstruction performance is evaluated before and after calibration. The results show that, with a reconstruction length of 25 cm, the average tip position error is reduced from 28.12 to 2.50 mm.