Qinetiq Limited

The Secretary of State for Defence in Her Britannic Majesty's Government

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

The Secretary of State for Defense in Her Britannic Majesty's Government

Alan H Greenaway

Peter A Lloyd

Roy McBride

James G Burnett

Paul M Blanchard

Philip St John Russell

Julian D Jones

Andrew Robert Harvey

Jonathan Cave Knight

Timothy Adam Birks

Robin Dickson

Paul Harrison

Philip S Russell

David G Luke

A three-dimensional imaging system is described which exploits the defocusing of non-zero diffraction order images caused by the quadratic distortion of a diffraction grating (). An optical system () is used such that objects (and), located at different distances from grating (), are imaged simultaneously and spatially separated on a single plane B.

Three-dimensional imaging system

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 infra-red imaging system has two variable focal length optical components ( ) whose positions are fixed relative to one another. The system also comprises an image detector ( ). Control means ( ) is provided such that the focal length of one of the variable focal length optical components ( ) can be varied in relation to the focal length of the other variable focal length optical component ( ). The system can be used to produce an image of variable magnification while maintaining an in-focus image at the detector ( ). The control means ( ) may comprise a mechanical linkage, an electronic circuit, or a computer program. In an alternative embodiment the optical system is a beam expander. Controlling a focusing mirror can achieve a dither effect. Controlling a focusing mirror can also de-focus the image, giving a mean scene temperature evaluation.

Infra-red imaging systems and other optical systems

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.

Optical fiber bend sensor

An optical fiber for transmitting radiation comprising two or more core regions, two or more core regions, each core region comprising a substantially transparent core material and having a core refractive index, a core length, and a core diameter, wherein said core regions are arranged within a cladding region, said cladding region comprising a length of first substantially transparent cladding material, having a first refractive index, wherein said first substantially transparent cladding material has an array of lengths of a second cladding material embedded along its length, wherein the second cladding material has a second refractive index which is less than said first refractive index, such that radiation input to said fiber propagates along at least one of said core regions. The cladding region and the core regions may be arranged such that radiation input to said optical fiber propagates along one or more said lengths of said core regions in a single mode of propagation. The optical fiber may be used as a bend sensor, a spectral filter or a directional coupler. The invention also relates to a method of manufacturing a multicore optical fiber.

Multicore optical fibre

Sensor system

Sensor system for measurement of temperature or strain

Growing community of inventors

Malvern, United Kingdom

Alan H Greenaway