Jones birefringence in twisted single-mode optical fibers

Abstract

In this work we analyze the birefringence matrix developed for a twisted fiber in order to identify the basic optical effects that define its birefringence. The study was performed using differential Jones calculus. The resultant differential matrix showed three independent types of birefringence: circular, linear at 0 degrees and linear at 45 degrees (Jones birefringence). We applied this birefringence matrix to the description of the output state of polarization measured for three commercial fibers that due to its higher rigidity present stronger birefringence changes when twisted. The torsion applied to the erbium-doped fiber samples varied from 0 to 1440 degrees.

Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review

“…Twist induced birefringence has been a topic of investigation since the early era of fibers. Fundamental investigations of this phenomenon date back to the late 1970s, early 1980s [4,5] and have continued up to recent years [6,7,8,9]. Twisting of a single-mode fiber causes two effects:

Appearance of circular birefringence (which is also demonstrated as an appearance of optical activity).

Modulation of linear birefringence, if linear birefringence pre-exists in the sensing fiber.

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“…In general, three distinctive situations can occur: (1) When intrinsic linear birefringence is very low as, for example, in modern Telecom Singlemode Fiber (SMF), polarization effects related to the modulation of the linear birefringence are insignificant and circular birefringence related effects prevail (i.e., optical activity); (2) When fibers with low, but non-negligible, intrinsic linear-birefringence are twisted, the appearance of circular birefringence combines with linear birefringence modulation, which leads to the appearance of elliptical birefringence and complex polarization evolution along the fiber length [8,9]. Examples like this are some (highly) doped, but otherwise circular fibers when exposed to twisting; (3) When the fiber is Highly Linearly Birefringent (HLB), twist-induced effects related to linear birefringence modulation dominate, and effects related to the presence of circular birefringence become insignificant.…”

Polarization dynamics in twisted fiber amplifiers: a non-Hermitian nonlinear dimer model

“…The natural and mechanically induced birefringence of the fiber provide for polarization mode-coupling, which has been used to design polarization rotators, polarization-mode interchangers, and delay equalizers [3,4,5,6]. Related to this, we assume polarization instability that might be caused by rare-earth doping and Kerr nonlinearity [7,8,9].…”

Statistical Model and Performance Analysis of a Novel Multilevel Polarization Modulation in Local “Twisted” Fibers

“…All of them act randomly along optical fibers. Circular birefringence may be generated, instead, by an external magnetic field aligned with the axis of propagation, or by twisting the fiber itself [1,2]. Basic models of the optical fiber birefringence have been described in [3,4].…”