Doctoral Dissertations

Keywords and Phrases

Capacity of an optical channel


"Light transmission through photo-sensitive multi-mode fibers (MMF) with controlled volume disorder is investigated. Experiment shows that a segment of disordered MMF as short as 10 cm is sufficient to distribute power uniformly over all co-propagating modes and the intensity at the output surface of the fiber follows the Rayleigh negative exponential function. To explain the experimental findings, a comprehensive theoretical model is developed with three main results. First, statistical properties of all components of the dielectric tensor are obtained and analyzed in the framework a microscopical model of photo-sensitivity in a germano-silicate glasses. Secondly, it is shown that induced birefringence is insufficient to explain mode mixing, and that cross-polarization mode coupling is essential. Such a coupling is shown to originate from the spatial correlation in the off-diagonal elements of the dielectric tensor. Third, a hybrid theory to describe propagation in a fiber with a spatially correlated disorder is developed. The proposed theory treats the deterministic part of the light via coupled-amplitude equations, and the randomly-phased component with coupled-power equations. The complete theory developed in this work has a predictive power -- it can guide the design of an artificial disorder based on the desired transmission properties of the fiber. Experiment shows that mixing all co-propagating modes can, indeed, be attained in a short segment of a suitably designed disordered MMF without a prohibitive loss. Such fibers can be useful for e.g. maximizing the information capacity multi-mode fiber links"--Abstract, page v.


Yamilov, Alexey

Committee Member(s)

Peacher, Jerry
Zheng, Y. Rosa
Story, J. Greg
Gao, Jie



Degree Name

Ph. D. in Physics


University of Missouri Research Board
National Science Foundation (U.S.)


Missouri University of Science and Technology

Publication Date

Fall 2013

Journal article titles appearing in thesis/dissertation

  • Fabrication, characterization and theoretical analysis of controlled disorder in the core of the optical fibers
  • Artificially disordered birefringent optical fibers
  • Investigation of mode coupling in optical fiber with controlled volume disorder


79 pages

Note about bibliography

Includes bibliographical references (pages 73-78).


© 2013 Herath Mudiyanselage Sumudu Rasika Kumari Herath, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Subject Headings

Optical fibers -- Analysis
Dielectrics -- Optical properties
Order-disorder models
Phase transformations (Statistical physics)
Refraction, Double

Thesis Number

T 10397

Electronic OCLC #


Included in

Physics Commons