Comments about birefringence dispersion, with group and phase birefringence measurements in polarization-maintaining fibers

• Published in: Journal of the European Optical Society. Rapid publications Vol. 19; no. 1; p. 1
• Main Authors: Villedieu, Thomas, Lablonde, Laurent, Boiron, Hugo, Steib, Adrien, Mélin, Gilles, Robin, Thierry, Cadier, Benoît, Rattier, Maxime, Lefèvre, Hervé C.
• Format: Journal Article
• Language: English
• Published: European Optical Society 2023; EDP Sciences
• Subjects: birefringence; birefringence dispersion; channeled-spectrum analysis; Engineering Sciences; group birefringence; phase birefringence; polarization-maintaining fiber; polarization-mode dispersion
• ISSN: 1990-2573; 1990-2573
• DOI: 10.1051/jeos/2022014

A recent JEOS-RP publication proposed Comments about Dispersion of Light Waves , and we present here complementary comments for birefringence dispersion in polarization-maintaining (PM) fibers, and for its measurement techniques based on channeled spectrum analysis. We start by a study of early seminal papers, and we propose additional explanations to get a simpler understanding of the subject. A geometrical construction is described to relate phase birefringence to group birefringence, and it is applied to the measurement of several kinds of PM fibers using stress-induced photo-elasticity, or shape birefringence. These measurements confirm clearly that the difference between group birefringence and phase birefringence is limited to 15–20% in stress-induced PM fibers (bow-tie, panda, or tiger-eye), but that it can get up to a 3-fold factor with an elliptical-core (E-core) fiber. There are also surprising results with solid-core micro-structured PM fibers, that are based on shape birefringence, as E-core fibers.