Qinetiq Limited

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

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

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

Richard Michael Jenkins

Mark Edward McNie

John M Heaton

Robert W Devereux

James McQuillan

David J Combes

Craig D Stacey

Brian Sinclair Lowans

Ewan David Finlayson

Christopher A Hill

James R Redding

Nicola Price

Philip C Conder

An optical receiver for a quantum key distribution system comprises a plurality of optical components mounted or formed in a substrate and optically coupled by one or more hollow core waveguides formed in the substrate.

Optical transmitters and receivers for quantum key distribution

A variable optical attenuator device is described that comprises a first optical input, a first optical output, a first optical path between the first optical input and the first optical output, and means for moving a shutter across said first optical path. A hollow core waveguide is provided to substantially guide light along the first optical path of the device. The device may also be used to provide an analogue beam splitting or switch function in telecommunication systems and the like.

Variable optical attenuator comprising hollow core waveguide

An optical routing device is described that comprises a semiconductor substrate () having at least one optical input (), a plurality of optical outputs () and an array of MEMS moveable reflective elements (). The array of moveable reflective elements () are configurable such that light can be selectively routed from any one optical input () to any one of two or more of said plurality of optical outputs (). Light selectively routed from any one optical input to any one of two or more of said plurality of optical outputs () is guided within a hollow core waveguide (). In one embodiment, a cross-connect optical matrix switch is described.

Optical routing device comprising hollow waveguides and MEMS reflective elements

A transmitter apparatus () is described that comprises one or more lasers (), modulation means () to intensity modulate radiation output by each of said one or more lasers (), and output means for outputting the modulated radiation produced by the modulation means into, for example, an optical fiber (). The apparatus comprises hollow core optical waveguides () formed in a substrate () which, in use, guide radiation from the one or more lasers () to the modulation means () and from the modulation means () to the output means. An associated receiver apparatus () is also described that comprises one or more detectors () and one or more optical fiber attachment means, the one or more optical fiber attachment means being arranged to receive one or more one optical fibers (). The receiver is characterized in that radiation is guided from the one or more optical fibers () to the one or more detectors () by at least one hollow core optical waveguide () formed in a substrate. A combined receiver/transmitter apparatus () is also shown.

Monolithic optical transmitter and receiver apparatus incorporating hollow waveguides

An optical wavelength division multiplexer/demultiplexer device is described that comprises a substrate having a plurality of wavelength selecting filters. The filters are arranged to provide conversion between a combined beam comprising a plurality of wavelength channels and a plurality of separate beams each comprising a subset of said plurality of wavelength channels. Hollow core waveguides are formed in said substrate to guide light between the wavelength selecting filters. An add/drop multiplexer is also described.

Optical wavelength division multiplexer/demultiplexer device

A photonic light circuit device is described that comprises a semiconductor substrate () and two or more optical components () wherein one or more hollow core optical waveguides () are formed in the semiconductor substrate to optically link said two or more optical components. The PLC may comprise a lid portion () and a base portion (). The PLC can be adapted to receive optical components () or optical components may be formed monolithically therein. Coating with a reflective layer is also described.

Optical circuit fabrication method and device

A hollow core multi-mode interference (MMI) device is described that comprises a multi-mode waveguide () optically coupled to at least two fundamental mode waveguides (). The device is characterised in that it comprises a means for varying the internal cross-sectional dimensions of a portion of one or more of said at least two fundamental mode waveguides. In particular, the side wall of a fundamental mode waveguide having a substantially square cross-section can be moved using micro-electro mechanical systems (MEMS). Various optical routing devices incorporating such MMI devices are described.

Hollow core multi-mode interference optical device

An optical amplifier is described that comprises at least two sections of amplifying optical fibre and pumping means for optically pumping the amplifying optical fibre. Optical fibre support means, for example a channel or channels in a substrate, are also provided to hold the two or more sections of amplifying optical fibre substantially straight during use. The optical fibre support means also includes a means for coupling light between the at least two sections of amplifying optical fibre. The at least one amplifying optical fibre may comprise an Erbium doped core to provide an erbium doped fibre amplifier (EDFA).

Optical fibre amplifier

Optical circuits for optical amplifier input and output stages are described. The input stage circuit () comprises a first optical waveguide () for carrying a signal beam to be amplified, a second optical waveguide () for carrying a pump beam, a beam combining means () optically coupled to the first and second optical waveguides () for producing a combined signal/pump beam, and means for optically coupling the combined signal/pump beam into an amplifying optical fibre (). The output stage circuit () comprises a first output optical waveguide (), an optical fibre attachment means arranged to receive an amplifying optical fibre () and an optical fibre attachment means arranged to receive an output optical fibre () wherein light from the amplifying optical fibre () is optically coupled to the output optical fibre () via the first output optical waveguide (). The first and second optical waveguides () and the first output optical waveguide () are hollow core optical waveguides formed as channels in a substrate. A fibre amplifier, in particular an erbium doped fibre amplifier, comprising such optical circuits is also described.

Optical amplifier

A multi-mode interference (MMI) device, comprising a hollow core multi-mode waveguide optically coupled to at least one hollow core input waveguide, is described in which the internal surfaces of the hollow core waveguides carry a reflective coating. The coating may be a low refractive index material at the wavelength of operation, such as a metal, or a multiple layer dielectric stack. Resonators and optical amplifiers using such (MMI) devices are also described.

Multi-mode interference optical waveguide device

An optical filter () comprises a multimode waveguide () and first () and second () coupling waveguides which communicate with lateral sides of the multimode waveguide. The filter operates by reproducing an optical field distribution input to the multimode waveguide via one of the coupling waveguides at the position in the multimode waveguide where the other coupling waveguide communicates with the multimode waveguide. This occurs for radiation of a wavelength to be filtered but not for radiation of other wavelengths.

Optical filter

An optical multiplexer and demultiplexer (mux-demux) () comprises a multimode waveguide () which communicates with first () and second () coupling waveguides. Multiplexed optical radiation comprising individual wavelength channels of appropriate wavelength introduced into the input waveguide is demultiplexed by means of modal dispersion and in-ter-modal interference with the multimode waveguide. The mux-demux consists of merely of waveguides and is therefore simple to fabricate and integrate with other components in integrated optical systems, and is capable of resolving channels having a small (&#x2dc;1 nm) wavelength spacing. The mux-demux may be used without modification as a demultiplexer and remains of simple construction when scaled up to operate with many channels.

Optical multiplexer and demultiplexer

An optical filter comprises a multimode waveguide, and first and second coupling waveguides which communicate with the multimode waveguide at respective ends thereof. Filtering is achieved by the effect of self-imaging in the multimode waveguide. The filter further comprises one or more series of aperture within the multimode waveguide, the or each series being located at a longitudinal position within the multimode waveguide at which 1-to-N way intensity division of an input optical field occurs, the optical field being the lowest order transverse mode of the coupling waveguides. The (one or more) series of apertures reduces the transmission of the filter at wavelength other than those corresponding to transmission peaks of filter's transmission function, thus providing improved filtering performance compared to prior art optical filters based on self-imaging.

A radiation field analyzer (10) provides means for analyzing the spatial mode spectrum of radiation received from a scene. In a multimode waveguide embodiment, light from a laser (24) is directed towards a scene through an alumina waveguide structure (12). A portion of the laser light is directed towards a mode generator (28) which selectively converts the laser radiation into one of a series of modes. Laser light returning from the scene is mixed with the light from the mode generator to produce interference signals. These signals are measured by a detector (34) and analyzed by a programmed computer (36). By sequentially altering the mode generated by the generator (28) and analyzing the resulting signals, a spectrum of the modes returning from the scene is obtained.

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Malvern, United Kingdom

Richard Michael Jenkins