Large range linear torsion sensor based on a suspended-core fiber loop mirror

Abstract

A fiber loop mirror containing a section of high-birefringence suspended-core fiber is used for torsion sensing. The suspended-core fiber section has a triangular-shaped core with an in-circle diameter of approximately 1.8 μm. Due to its small dimensions and geometric structure, it presents high birefringence and intermodal interference simultaneously. A torsion sensitivity of 59.0 pm/ deg is obtained in a very large linear range of 900 deg with a resolution of 1.2 deg. © 2013 Society of Photo-Optical Instrumentation Engineers (SPIE).