In multi mode optical fibers degenerated modes occur, which cannot be discriminated by their propagation properties. Hence, in principle any arbitrary superposition of these degenerated modes can be used to build an equivalent set of modes. In a perturbed system this degeneracy can be broken, and as a consequence -not every superposition represents real modes of the fiber. In mode division multiplexing system this leads to high inter-modal crosstalk, if unsuitable (initially degenerated) modes are chosen. Based on the analysis of the fiber’s transmission matrix, we present a measurement scheme to prove degeneracy breaking and to identify physical non-degenerated modes.

Date Published: 7 February 2015
PDF: 8 pages
Proc. SPIE 9389, Next-Generation Optical Communication: Components, Sub-Systems, and Systems IV, 93890O (7 February 2015); doi: 10.1117/12.2078733

Published in SPIE Proceedings Vol. 9389:
Next-Generation Optical Communication: Components, Sub-Systems, and Systems IV
Guifang Li; Xiang Zhou, Editor(s)