Crystal Fibre A/s

Qinetiq Limited

Nkt Photonics A/s

Blazephotonics Limited

Philip St John Russell

Timothy Adam Birks

Jonathan Cave Knight

Brian Joseph Mangan

David Philip Williams

Peter John Roberts

Hendrik Sabert

Alan H Greenaway

Peter A Lloyd

Andrew Robert Harvey

Paul M Blanchard

James G Burnett

Roy McBride

Alexander Onischenko

William Wadsworth

Ian Patrick Kilbride

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

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

Improved photonic band-gap optical fibre The present invention relates in particular to improved photonic band-gap optical fibres that can confine light to a core region of the fibre by the action of both a photonic band-gap cladding and an antiresonant core boundary, at the interface between the core and cladding. According to embodiments of the present invention, a fibre has a core, comprising an elongate region of relatively low refractive index, a photonic bandgap structure arranged to provide a photonic bandgap over a range of wavelengths of light including an operating wavelength of light, the structure, in a transverse cross section of the waveguide, surrounding the core and comprising elongate relatively low refractive index regions interspersed with elongate relatively high refractive index regions and a relatively high refractive index boundary at the interface between the core defect and the photonic bandgap structure, the boundary having a thickness around the core such that the boundary is substantially anti-resonant at the operating wavelength of the fibre. In preferred embodiments, the core boundary is a relatively constant thickness region of glass around a hollow core.

Photonic bandgap optical waveguide with anti-resonant core boundary

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).

Novel preforms and methods of making novel preforms are described. The preforms are suitable for being drawn into photonic bandgap optical fibres. In one form, the preform comprises a stack of elongate members having, in transverse cross section, a triangular close-packed arrangement of circular cross section capillaries, which define interstitial regions containing solid rods. The stack is supported around a relatively large capillary, which defines an inner region of the stack. The stack may be adapted by varying the number of rods in any given interstitial region, in order to generate various different configurations of cladding structure, which can be made into optical fibres having surprising operational characteristics, such as a split gap.

Enhanced optical waveguide

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

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 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 ( ).

An optical fibre bend sensor ( ) measures the degree and orientation of bending present in a sensor length ( ) portion of a fibre assembly ( ). Within a multicored fibre ( ), cores ( ) are grouped in non-coplanar pairs. An arrangement of optical elements ( ) define within each core pair ( ) two optical paths ( ) which differ along the sensor length ( ): one core ( ) of a pair ( ) is included in the first path ( ), and the other core ( ) in the second path ( ). A general bending of the sensor region ( ) will lengthen one core ( ) with respect to the other. Interrogation of this length differential by means of interferometry generates interferograms from which the degree of bending in the plane of the core pair is extracted. Bend orientation can be deduced from data extracted from multiple core pairs.

Optical fibre bend sensor

An optical fiber bend sensor ( ) measures the degree and orientation of bending present in a sensor length ( ) portion of a fiber assembly ( ). Within a multicored fiber ( ), cores ( ) are grouped in non-coplanar pairs. An arrangement of optical elements ( ) define within each core pair ( ) two optical paths ( ) which differ along the sensor length ( ): one core ( ) of a pair ( ) is included in the first path ( ), and the other core ( ) in the second path ( ). A general bending of the sensor region ( ) will lengthen one core ( ) with respect to the other. Interrogation of this length differential by means of interferometry generates interferograms from which the degree of bending in the plane of the core pair is extracted. Bend orientation can be deduced from data extracted from multiple core pairs.

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Bath, United Kingdom

Philip St John Russell