We develop and experimentally verify a theory of evolution of polarization in artificially-disordered multi-mode optical fibers. Starting with a microscopic model of photo-induced index change, we obtain the first and second order statistics of the dielectric tensor in a Ge-doped fiber, where a volume disorder is intentionally inscribed via UV radiation transmitted through a diffuser. A hybrid coupled-power & coupled-mode theory is developed to describe the transient process of de-polarization of light launched into such a fiber. After certain characteristic distance, the power is predicted to be equally distributed over all co-propagating modes of the fiber regardless of their polarization. Polarization-resolved experiments, confirm the predicted evolution of the state of polarization. Complete mode mixing in a segment of fiber as short as ~ 10cm after 3.6dB insertion loss is experimentally observed. Equal excitation of all modes in such a multi-mode fiber creates the conditions to maximize the information capacity of the system under e.g. multiple-input-multiple-output (MIMO) transmission setup.
S. Herath et al., "Artificially Disordered Birefringent Optical Fibers," Optics Express, vol. 20, no. 4, pp. 3620 - 3632, Optical Society of American (OSA), Feb 2012.
The definitive version is available at https://doi.org/10.1364/OE.20.003620
Keywords and Phrases
Fibers; Germanium; Optical Fibers; Ultraviolet Radiation; Birefringent Optical Fiber; Characteristic Distance; Coupled-mode Theory; Dielectric Tensors; Ge-doped Fibers; Microscopic Models; Multimodes; Multiple-input-multiple-output; Photo-induced; Second Order Statistics; State Of Polarization; Theory Of Evolution; Transient Process; Polarization
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© 2012 Optical Society of American (OSA), All rights reserved.
01 Feb 2012