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US 2004/0175084 A1Published application
Novel photonic bandgap fibre, and use thereof
AssigneeCrystal Fibre A/S
InventorsJes Broeng, Stig Eigil Barkou Libori, Anders Bjarklev
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AssigneeCrystal Fibre A/S
InventorsJes Broeng, Stig Eigil Barkou Libori, Anders Bjarklev
Estimating the term…
An object of the present invention is to provide new designs of microstructured optical fibres that may be fabricated without use of voids, such as fibres being realized using silica and silica doping techniques. The invention relates to a mircrostructured optical fibre that guides light in a core region (52), where the fibre has a cladding region that comprises a background material (51) and a number of cladding features or elements (50) that are elongated in the longitudinal direction of the fibre and have a higher refractive index than the cladding background material. The core region has a lower effective refractive index than the cladding, and the fibre may guide light in the core by photonic bandgap effects. The present invention provides designs of photonic bandgap fibres that may operate without the use of voids in the cladding, thereby simplifiying fabrication of photonic bandgap fibres compared to prior art. The invention further provides photonic bandgap fibers with tuneable waveguiding properties, such as tuneable polarization. The invention further relates to a number of specific fibre designs that provide improvements with respect to dispersion characteristics, mode field diameters, propagation losses, polarizaton mode dispersion and other issues of relevance to optical communication systems.
A micro-structured optical fibre for guiding light at an operating wavelength, said optical fibre having an axial direction and a cross section perpendicular to said axial direction, said optical fibre comprising:
A micro-structured optical fibre having an axial direction and a cross-section perpendicular to said axial direction, said optical fibre comprising:
A micro-structured optical fibre having an axial direction and a cross-section perpendicular to said axial direction, said optical fibre comprising:
A micro-structured optical fibre for guiding light at an operating wavelength, said optical fibre having an axial direction and a cross-section perpendicular to said axial direction, said optical fibre comprising:
A micro-structured optical fibre according to any one of the preceding claims, wherein said high-index cladding features are elongated in the fibre axial direction.
A micro-structured optical fibre according to any one of the preceding claims, wherein the optical fibre is a Photonic Bandgap Fibre.
A micro-structured optical fibre for transmitting at least a predetermined wavelength of light, said optical fibre having an axial direction and a cross section perpendicular to said axial direction, said optical fibre comprising:
A micro-structured optical fibre according to any one of the preceding claims, wherein the fabrication of the fibre comprises stacking of doped silica rods.
A micro-structured optical fibre according to any one of the preceding claims, comprising in a preform therefore stacking of doped silica rods and at least one.
A micro-structure optical fibre according to any one of the preceding claims, wherein the difference in the refractive index of the high index cladding features and the low-index cladding background material is equal to or lower than 5%, equal to or lower than 4%, equal to or lower than 3%, equal to or lower than 2%, equal to or lower than 1%, or equal to or lower than 0.5% of the refractive index of the high-index cladding features.
A micro-structured optical fibre according to any one of the preceding claims, wherein the fibre solely comprises materials having refractive indices in the range from 1.43 to 1.48, in the range from 1.44 to 1.47, or in the range from 1.44 to 1.46.
A micro-structured optical fibre according to any one of the preceding claims, wherein a centre-to-centre spacing of nearest cladding features is larger than said predetermined wavelength or the operating wavelength of guided light, such as larger than 2 times than said predetermined or operating wavelength, such as larger than 5 times than said predetermined or operating wavelength.
A micro-structured optical fibre according to any one of the preceding claims, wherein said predetermined wavelength or the operating wavelength of guided light is selected from wavelengths in the interval of 0.3 μm to 2 μm.
A micro-structured optical fibre according to any one of the preceding claims, wherein said predetermined wavelength or the operating wavelength of guided light is selected from wavelengths in the interval of 0.6 μm to 1.2 μm.
A micro-structured optical fibre according to any one of the preceding claims, wherein said predetermined wavelength or the operating wavelength of guided light is selected to be about 0.78 μm, about 0.98 μm, or about 1.06 μm.
A micro-structured optical fibre according to any one of the preceding claims, wherein the core region has a diameter larger than or equal to 2 μm.
A micro-structured optical fibre according to any one of the preceding claims, wherein the core material and/or the first cladding material is silica.
A micro-structured optical fibre according to any one of the preceding claims, wherein the cladding features in the cross-section have a non-circular shape, such as an elliptical shape or a rectangular shape.
A micro-structured optical fibre according to any of the preceding claims, wherein the core and/or the cladding comprises a material selected from the group:
A micro-structured optical fibre according to any one of the preceding claims, wherein said fibre is dimensioned to guide light of the predetermined or operating wavelength in two substantially, non-degenerate polarization states.
A micro-structured optical fibre according to any one of the preceding claims, wherein the shape of the core region deviates substantially from a circular shape in the fibre cross-section.
A micro-structured optical fibre according to any one of the preceding claims, wherein the shape of the core region is substantially rectangular in the fibre cross-section.
A micro-structured optical fibre according to any one of the preceding claims, wherein the core region and/or cladding region has substantially a 180 degree rotational symmetry in the fibre cross-section.
A micro-structured optical fibre according to any one of the preceding claims, wherein said core and cladding region being mutually adapted so that the fibre exhibits large anomalous dispersion of more than 100 ps/nm/km at a wavelength in the range from 1.4 μm to 1.7 μm, said core region having a diameter of more than 4 μm, such as a core diameter of around 5 μm.
A micro-structured optical fibre according to any one of the preceding claims, wherein said core and cladding region being mutually adapted so that the fibre exhibits large anomalous dispersion of more than 200 ps/nm/km at a wavelength in the range from 1.3 am to 1.7 μm, said core region having a diameter of more than 2 micrometer, such as a core diameter of around 4 μm.
A fibre optical communication system of part thereof, wherein a micro-structured optical fibre according to any one of the preceding claims is employed for dispersion control.
A micro-structured optical fibre according to any one of the preceding claims, wherein said core and cladding region being mutually adapted so that the fibre exhibits anomalous dispersion over a wavelength range from at least 1.2 μm to 1.7 μm.
Dependencies are inferred from the claim text.