OFDR with local spectrum matching method for optical fiber shape sensing

Abstract

Strain measurement is the basis of shape reconstruction by using the optical frequency domain reflectometer, and we propose a local spectrum matching method to determine the strain induced wavelength shift by matching the most similarity portion in the measurement spectrum. Comparison study between conventional cross-correlation and local spectrum matching indicates that the proposed method can effectively eliminate the fake peaks and multi-peaks of the cross-correlation. Shape sensing experiments after the calibration process of the curvature illustrate that the two-dimensional shape reconstruction error can be as low as 1 cm in a sensing fiber length of 1 m.