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.
Claims29
A photonic bandgap fiber having a transmission band comprising:
- a core;
- and
- a cladding disposed about said core comprising a first plurality of regions defined by high index material having an index of refraction, nh, and a second plurality of regions having a low index of refraction, nl,
- wherein said high index region closest to said core has a thickness, δ, such that δ(nh2−nl2)1/2/λ has a value between approximately 0.01 to 0.2, such that said fiber has zero dispersion at a wavelength in the transmission band.
A photonic bandgap fiber having a transmission band comprising:
- a core;
- and
- a cladding disposed about said core, said cladding comprising a first plurality of regions defined by high index material having an index of refraction, nh, and a second plurality of regions having a low index of refraction, nl, said first plurality of high index regions having an average thickness, d, and an average periodicity, Λ, such that the ratio d/Λ is less than about 0.3,
- wherein said fiber has a dispersion between about −100 to 100 ps/nm/km over at least about 100 nm of said transmission band, and
- wherein said fiber is configured to have a confinement loss less than 10 dB/km over at least about 100 nm of said transmission band.
Dependencies are inferred from the claim text.