title: Measurement and suppression of secondary waves caused by high-order modes in a photonic bandgap fiber-optic gyroscope.
abstract: Air-core photonic bandgap fiber (PBF) is a good choice for fiber-optic gyroscopes (FOGs) owing to the fact that it can be adapted to a wide variety of environments. However, its multimode properties are disadvantageous for the application to FOGs. An interference-based method is proposed to precisely determine the secondary waves caused by the high-order modes and their coupling. Based on the method, two groups of secondary waves have been found, having optical path differences (OPDs) of ~1.859 m and ~0.85 m, respectively, relative to the primary waves in a PBFOG that consists of a 7-cell PBF coil, approximately 180 m in length. Multi-turn bends of the PBF at both ends of the PBF coil after the fusion splicing points are shown to suppress the intensity of these secondary waves by approximately 10 dB.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Xu
authors.forename: Fuyu
authors.initials: F
authors.lastname: Gao
authors.forename: Ningfang
authors.initials: N
authors.lastname: Song
authors.forename: Jing
authors.initials: J
authors.lastname: Jin