Polarization evolution in bent spun fiber

• Published in: Journal of lightwave technology Vol. 23; no. 11; pp. 3815 - 3820
• Main Authors: Polynkin, P., Blake, J.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-11-2005; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplitudes; Applied sciences; Bending; Birefringence; Circuit properties; Coiling; Coils; current sensor; Electric, optical and optoelectronic circuits; Electronics; Evolution; Exact sciences and technology; Fibers; Integrated optics. Optical fibers and wave guides; Magnetic field measurement; Magnetic sensors; Optical and optoelectronic circuits; Optical fiber polarization; Optical fiber sensors; Optical fiber theory; Optical fibers; Oscillations; Polarization; spun fiber; Temperature dependence; Temperature sensors; Performance evaluation; Integrated optics; Perturbation theory; Current sensor; Single mode fiber; Birefringence; spun fiber; Optical fiber
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2005.855865

Since its introduction over a decade ago, the spun birefringent single-mode optical fiber is increasingly being considered for current-sensing applications. In this paper, we study the behavior of such a fiber when it is bent into a sensing coil. We show that bending weakens the polarization-holding capability of the spun birefringent fiber and causes the average polarization state to slowly oscillate along the fiber, potentially degrading the performance of the current sensor. The amplitude of this oscillation increases with tighter bending. Both the amplitude and the period of this oscillation, which are important parameters for designing current-sensing coils, are calculated by applying an appropriate perturbation theory. An experiment confirming the theory is also reported.