Patent ID: 7228041
Filing Date: 2007-06-05
Classification: G02B

Abstract:
1. A photonic-bandgap fiber comprising: a photonic crystal lattice comprising a first material having a first refractive index, the first material having a pattern of a second material formed therein, the second material having a second refractive index lower than the first refractive index, the photonic crystal lattice having a plurality of first regions that support intensity lobes of the highest frequency bulk mode and having a plurality of second regions that do not support intensity lobes of the highest frequency bulk mode; a central core formed in the photonic crystal lattice; and a core ring having an inner perimeter and an outer perimeter, the core ring surrounding the central core, wherein the outer perimeter of the core ring passes only through the second regions of the photonic crystal lattice; wherein the core ring has a thickness between the inner perimeter and the outer perimeter, the thickness sized to reduce the number of ring surface modes supported by the core ring.