Open AccessA non-orthogonal coupled mode theory for super-modes inside multi-core fibers
Author(s) -
Junhe Zhou
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.010815
Subject(s) - coupled mode theory , optics , eigenvalues and eigenvectors , fourier transform , inverse , physics , coupling (piping) , mode (computer interface) , core (optical fiber) , ray transfer matrix analysis , refractive index , materials science , computer science , mathematics , quantum mechanics , geometry , metallurgy , operating system
In this paper, a non-orthogonal coupled mode theory is proposed to analyze the super-modes of multi-core fibers (MCFs). The theory is valid in the strong coupling regime and can provide accurate analytical formulas for the super-modes inside MCFs. MCFs with circularly distributed cores are analyzed as an example. Analytical formulas are derived both for the refractive indexes and the eigen vectors of the super-modes. It is rigorously revealed that the eigen vectors for the super-modes of such MCFs are the row vectors of the inverse discrete Fourier transform (IDFT) matrix. Therefore, by pre-coding the signal channels via IDFT, one is able to generate the super-modes for the MCFs with circularly distributed cores.