Open AccessDesign strategies and rigorous conditions for single-polarization single-mode waveguides
Author(s) -
Karen K. Y. Lee,
Yehuda Avniel,
Steven G. Johnson
Publication year - 2008
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.16.015170
Subject(s) - cladding (metalworking) , optics , degenerate energy levels , polarization (electrochemistry) , single mode optical fiber , refractive index , dielectric , waveguide , photonic crystal , photonic crystal fiber , materials science , physics , optoelectronics , optical fiber , chemistry , quantum mechanics , metallurgy
We establish rigorous necessary analytical conditions for the existence of single-polarization single-mode (SPSM) bandwidths in index-guided microstructured waveguides (such as photonic-crystal fibers). These conditions allow us to categorize designs for SPSM waveguides into four strategies, at least one of which seems previously unexplored. Conversely, we obtain rigorous sufficient conditions for the existence of two cutoff-free index-guided modes in a wide variety of microstructured dielectric waveguides with arbitrary periodic claddings, based on the existence of a degenerate fundamental mode of the cladding (a degenerate light line). We show how such a degenerate light line, in turn, follows from the symmetry of the cladding.