We examine localized surface modes in the core of a photonic crystal fiber composed of a finite nonlinear (Kerr) hexagonal waveguide array containing a topological defect in the form of a central void. Using the coupled-modes approach, we find the fundamental surface mode and the staggered and unstaggered ring-shaped modes, and their linear stability windows, for two void diameters. We find that, for a small void diameter, the unstable unstaggered ring mode of the system always requires less power and its instability gain at low powers is smaller than in the case without the void. Also, for the small void case, the unstaggered ring mode does not require a minimum power threshold, in sharp contrast with the case without the void. For a larger void, most of these observations hold, as well. We follow numerically the dynamical evolution of these ring modes to reveal their decay channels at long propagation distances.
© 2012 Optical Society of America
Original Manuscript: January 18, 2012
Revised Manuscript: June 13, 2012
Manuscript Accepted: June 26, 2012
Published: July 27, 2012
Francis H. Bennet and Mario I. Molina, "Nonlinear light localization around the core of a holey fiber," J. Opt. Soc. Am. B 29, 2161-2165 (2012)