Fiber curvature sensor based on concave‐heterotypic cascaded fiber Sagnac interferometer

Abstract

Abstract A fiber optical curvature sensor comprising a concave‐heterotypic cascaded fiber structure built into Sagnac loop is demonstrated experimentally. A section of multimode fiber is sandwiched between the single mode fiber and polarization maintaining fiber in order to construct the concave‐heterotypic cascaded fiber structure. The concave structure presented is used to effectively excite guided modes. The spectra of the proposed bending sensor will shift toward long wavelength with curvature. The measured the curvature sensitivity of 11.6 nm/m −1 has been achieved. The proposed curvature sensor characterizes cost‐efficient, simple fabrication process and can be used for health monitoring in civil engineering.

Topics & Concepts