Crystal Fibre A/s

Nkt Photonics A/s

The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland

Qinetiq Limited

Nkt Research & Innovation A/s

Blazephotonics Limited

Crystal Fibre A/c

Timothy Adam Birks

Jonathan Cave Knight

Philip St John Russell

Brian Joseph Mangan

Hendrik Sabert

David Philip Williams

Peter John Roberts

Philip St J Russell

Alexander Onischenko

Alan H Greenaway

Peter A Lloyd

William Wadsworth

David Bird

Philip S Russell

John Mark Pottage

Matthew James Banham

Ian Patrick Kilbride

Phillip St John Russell

A method of manufacturing a microstructured fiber, includes: providing a preform having a plurality of elongate holes; mating at least one, but not all, of the holes with a connector to connect the hole(s) to an external pressure-controller; drawing the preform into the fiber while controlling gas pressure in the hole(s) connected to the pressure-controller.

Method of drawing microstructured glass optical fibers from a preform, and a preform combined with a connector

A birefringent elongate waveguide for guiding light, comprises: a core region (), comprising an elongate region of relatively low refractive index; and a cladding region (), comprising elongate regions () of relatively low refractive index interspersed with elongate regions () of relatively high refractive index. In a transverse cross-section of the waveguide, a (5) relatively high refractive index boundary region () is provided that surrounds the core region and has either (1) at most two-fold rotational symmetry or (2) a rotational symmetry that reduces the rotational symmetry of the waveguide to at most two-fold rotational symmetry. The symmetry of the boundary region () results at least in part from azimuthal variations therein, which are substantially uncharacteristic of the cladding region ().

Birefringent photonic bandgap optical waveguide

An elongate waveguide for guiding light including a core having an elongate region of relatively low refractive index; a microstructured region around the core comprising elongate regions of relatively low refractive index interspersed with elongate regions of relatively high refractive index; and a boundary at the interface between the core and the microstructured region, the boundary including, in the transverse cross-section, a region of relatively high refractive index, which is connected to the microstructured region at a plurality of nodes, and at least one relatively enlarged region around the boundary, the enlarged region having a major dimension and a minor dimension, wherein the length of the major dimension divided by the length of the minor dimension is more than 3.0.

Optical waveguide

An elongate waveguide for guiding light includes a core having an elongate region of relatively low refractive index; a microstructured region around the core having elongate regions of relatively low refractive index interspersed with elongate regions of relatively high refractive index; and a boundary at the interface between the core and the microstructured region, the boundary including in the transverse cross-section, a region of relatively high refractive index, which is connected to the microstructured region at a plurality of nodes, at least one relatively enlarged region around the boundary (and excluding a boundary having twelve nodes and six enlarged regions substantially at a mid-point between six pairs of relatively more-widely-spaced apart neighboring nodes).

Photonic crystal fibers that guide light by virtue of a photonic band gap. Fibers that are formed from materials having higher refractive indices than silica are provided using an optical waveguide including a core with a relatively low refractive index and a photonic band gap structure that can substantially confine light to the core. The structure includes elongate regions of relatively low refractive index interspersed with elongate regions of relatively high refractive index, with the band gap residing above the fifth photonic band of the band gap structure.

Optical fibres

A holey optical fibre for supporting propagation of light of a wavelength &#x3bb;,comprises a plurality of cylinders () each having a longitudinal axis, the cylinders () being separated from each other by regions of a matrix material () and having their longitudinal axes substantially parallel to each other. Each cylinder () has a diameter, in the plane perpendicular to the longitudinal axis, that is small enough for the composite material of the ensemble of cylinders and matrix material to be substantially optically homogenous in respect of light of wavelength &#x3bb;.

Preform holey optical fibre, a holey optical fibre, and a method for their production

A method of joining a first optical fiber () to a second optical fiber () comprises the steps of: (i) providing a preform element () comprising material defining a primary elongate cavity (); (ii) inserting the first optical fiber () into the primary cavity () to form a preform (); and (iii) drawing the second optical fiber () from the preform (); wherein, the second optical fiber () includes a core region comprising material that has been drawn from the first optical fiber ().

Method and apparatus relating to optical fibers

A photonic crystal fiber comprising a bulk material having an arrangement of longitudinal holes, the fiber including a cladding region and a guiding core (), the cladding region having an effective-refractive-index which varies across the fiber's cross section, wherein, in use, the effective-refractive-index variation causes light propagating in the fiber to have a different transverse profile from the profile that it would have if the cladding region were of a substantially uniform effective refractive index.

Photonic crystal fibers

This invention relates to an optical fibre that comprises a core () of lower refractive index that is surrounded by a cladding which includes regions of a higher refractive index and is substantially periodic, where the core () has a longest transverse dimension that is longer than a single, shortest period of the cladding. In a fibre of this type light is substantially confined to the core area by virtue of the photonic band gap of the cladding material. The invention also relates to a method of manufacturing such an optical fibre, comprising the steps of forming a stack of canes (), the stack () including at least one truncated cane () that defines an aperture (), and then drawing the stack () into a fibre having an elongate cavity. The fibre is suitable for high power uses, but is equally suitable for other areas, e.g. optical amplifiers, spectral filters, lasers, gas sensors and telecommunications networks.

Photonic crystal fibre and a method for its production

A photonic crystal fiber comprising a bulk material having an arrangement of longitudinal holes () and a guiding core (), wherein the fiber has at-most-two-fold rotational symmetry about a longitudinal axis and as a result of that lack of symmetry, the fiber is birefringent.

Photonic crystal fibres

In a method of producing a photonic crystal fibre, a preform () that includes holes is formed and the preform () is drawn into a fibre. The method includes the step of applying a pressure differential to certain of the holes to control changes in the fibre structure during the draw.

A photonic crystal fiber comprising: a core () having a refractive index; and a cladding region () at least substantially surrounding the core () and comprising a bulk material having a second refractive index that is higher that the first refractive index, the bulk material containing an arrangement of elongate, longitudinal holes that comprise hole material of a third refractive index that is lower than the first refractive index; such that an electromagnetic mode guided in the core () has an evanescent wave that becomes more closely confined to the vicinity of the core () as the wavelength of the electromagnetic mode is increased over a first range of wavelengths.

Photonic-crystal fibers and photonic-crystal fiber devices

A photonic crystal fiber including a plurality of longitudinal holes ( ), in which at least some of the holes have a different cross-sectional area in a first region ( ) of the fiber, that region having been heat-treated after fabrication of the fiber, from their cross-sectional area in a second region of the fiber ( ), wherein the optical properties of the fiber in the heat-treated region ( ) are altered by virtue of the change in cross-sectional area of holes ( ) in that region ( ).

A large core photonic crystal fiber for transmitting radiation having a core comprising a substantially transparent core material and having a core diameter of at least 5&mgr;. The fiber also comprises a cladding region surrounding the length of core material, wherein the cladding region comprises a first substantially transparent cladding material, having a first refractive index, and wherein the first substantially transparent cladding material has embedded along its length a substantially periodic array of holes, wherein the holes are filled with a second cladding material having a second refractive index less than the first refractive index, such that radiation input to the optical fiber is transmitted along the length of the core material in a single mode of propagation. In a preferred embodiment, the core diameter may be at least 20&mgr;, and may be as large as 50&mgr;. The fiber is capable of transmitting higher power radiation than conventional fibers, whilst maintaining propagation in a single mode. The core material may be doped with a material capable of providing amplification under the action of pump radiation input to the fiber. The invention also relates to a fiber amplifier and a fiber laser comprising a doped large core photonic crystal fiber. The fibre may also be used in a system for transmitting radiation comprising a plurality of lengths of large core photonic crystal fiber, separated by large core photonic crystal fiber amplifiers, such that the power of radiation transmitted through the system is maintained above a predetermined threshold power.

Single mode optical fibre having a large cone photonic crystal

A large core photonic crystal fiber for transmitting radiation having a core comprising a substantially transparent core material and having a core diameter of at least 5 &mgr;. The fiber also comprises a cladding region surrounding the length of core material, wherein the cladding region comprises a first substantially transparent cladding material, having a first refractive index, and wherein the first substantially transparent cladding material has embedded along its length a substantially periodic array of holes, wherein the holes are filled with a second cladding material having a second refractive index less than the first refractive index, such that radiation input to the optical fiber is transmitted along the length of the core material in a single mode of propagation. In a preferred embodiment, the core diameter may be at least 20 &mgr;, and may be as large as 50 &mgr;. The fiber is capable of transmitting higher power radiation than conventional fibres, whilst maintaining propagation in a single mode. The core material may be doped with a material capable of providing amplification under the action of pump radiation input to the fiber. The invention also relates to a fiber amplifier and a fiber laser comprising a doped large core photonic crystal fiber. The fiber may also be used in a system for transmitting radiation comprising a plurality of lengths of large core photonic crystal fiber, separated by large core photonic crystal fiber amplifiers, such that the power of radiation transmitted through the system is maintained above a predetermined threshold power.

Growing community of inventors

Bath, United Kingdom

Timothy Adam Birks