Photonic bandgap fibers
AssigneeImra America, Inc.
InventorsLiang Dong, Xiang Peng
Life of this patent
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Abstract
Included among the many structures described herein are photonic bandgap fibers designed to provide a desired dispersion spectrum. Additionally, designs for achieving wide transmission bands and lower transmission loss are also discussed. For example, in some fiber designs, smaller dimensions of high index material in the cladding and large core size provide small flat dispersion over a wide spectral range. In other examples, the thickness of the high index ring-shaped region closest to the core has sufficiently large dimensions to provide negative dispersion or zero dispersion at a desired wavelength. Additionally, low index cladding features distributed along concentric rings or circles may be used for achieving wide bandgaps.
Claims14
A method of manufacturing a photonic bandgap fiber, said method comprising:
- arranging a plurality of tubes so as to form a plurality of rings of tubes disposed about a center;
- excluding at least three rings of tubes from said center to provide an open region;
- and
- stretching said plurality of tubes thereby reducing the size of said rings and said open region so as to form a photonic bandgap fiber comprising a core and a cladding disposed about said core, wherein said cladding includes a first plurality of ring shaped regions comprising a high refractive index material and a second plurality of ring shaped regions comprising a low refractive index material,
- wherein said first plurality of ring shaped regions has an average thickness, d, and an average periodicity, Λ, and said average thickness, d, of said high index material is limited such that the ratio d/Λ is less than approximately 0.2, and
- wherein said excluding and stretching affect an optical characteristic of said photonic bandgap fiber at a design wavelength.
Dependencies are inferred from the claim text.