British Telecommunications Public Limited Company

Huawei Technologies Co., Limited

British Telecommunications Corporation

Max-planck-gesellschaft Zur F&#xf6;rderung Der Wissenschaften E. V.

British Telecommunications Public Limited Company, a Corporation of England

Richard Wyatt

David W Smith

Jonathan R Armitage

David Cotter

Ian Lealman

Raman Kashyap

Keith H Cameron

Robert M Percival

Karl Boylan

Ramsey Selim

Jennifer F Massicott

Stephen A Cassidy

Michael J Robertson

Alistair James Poustie

David Graham Moodie

Graeme Douglas Maxwell

Douglas L Williams

Michael Charles Brierley

David C Rogers

Roger Alyn Payne

Robert J Campbell

Howard John Wickes

Salah A Al-Chalabi

Ernesto E Marinero

Gerard Sherlock

Robert John Campbell

Michael C Brain

John Mellis

David William Smith

Keith Henderson Cameron

Michael Charles Brain

Salah Ahmad Al-Chalabi

A multi-channel tunable laser includes: a frequency selective optical multiplexer comprising: a plurality of channel terminals for receiving/transmitting light; a plurality of channel waveguide blocks, each channel waveguide block comprising at least one reflectively terminated channel waveguide; and an optical coupling element optically coupling the plurality of channel terminals with the plurality of channel waveguide blocks, each of the channel waveguides of the plurality of channel waveguide blocks having a different length; a plurality of channel paths, each channel path coupled to a respective channel terminal of the plurality of channel terminals and comprising a gain element, a phase element and a reflective element; and a plurality of optical tuners, each one configured to tune the channel waveguides of a respective channel waveguide block of the plurality of channel waveguide blocks.

Multi-channel tunable laser

A tunable laser for tuning a lasing mode based on light beams travelling through at least one block of channel waveguides with at least two tunable combs, includes: a frequency selective optical multiplexer comprising a first terminal for receiving/transmitting light, at least one block of channel waveguides, each channel waveguide having a reflectively coated first tail and a second tail, and an optical coupling element optically coupling the first terminal with the second tails of the channel waveguides of the at least one block of channel waveguides, each of the channel waveguides having a different length; a gain element generating a broad spectrum of light, the gain element coupling the first terminal of the frequency selective optical multiplexer with a reflective element.

Tunable laser and method for tuning a lasing mode

A multiwavelength transmitter comprises several laser sources () each configured to generate light of a different wavelength and a first array waveguide grating () arranged to direct light from each of the laser sources () into a first waveguide. The transmitter further comprises several electroabsorption modulators () each arranged to modulate light at one of the wavelengths with a respective data signal and a second array waveguide grating () arranged to direct each of said different wavelengths of light from the first waveguide to a respective one of the modulators (). The optical modulators () are reflective optical modulators and the second array waveguide grating () is arranged to direct the modulated light reflected from each of the optical modulators () back into the first waveguide. An optical circulator () is provided in the first waveguide to couple modulated light from the second array waveguide grating () into an output waveguide. The laser sources each comprise a respective reflective semiconductor optical amplifier () and share a common cavity reflector (). The first array waveguide grating () is located in the optical path between the semiconductor optical amplifiers () and the common cavity reflector (). The transmitter has the advantage that it can be manufactured by hybrid integration of a monolithic wavelength generation sub-module and a monolithic data modulation sub-module.

Multiwavelength transmitter

A section of tapered optical fiber is provided to protect optical components from catastrophic damage that may propagate within an optical route. The tapered section functions as a fuse to arrest the propagation of optical power induced damage by leaking optical power from a waveguiding region below a threshold, below which further propagation of damage is not supported.

Optical communications system and method of protecting an optical route

A thulium doped silica based glass capable of supporting lasing activity including Tm as a lasing species disposed in a host composition, including oxides of germanium, silicon and tantalum. The preferred concentration of silicon in the host composition being between 15-25 weight percent. The preferred concentration of germanium in the host composition being between 0.1-1 weight percent. The preferred concentration of tantalum in the host composition is greater than 15 weight percent. The preferred concentration of thulium ions being in the range of 500-1000 parts per million by weight.

Silica glass composition with lasing properties, an optical waveguide and a method of amplifying optical signals

Gain controlled optical fibre amplifier

Laser

A high power monomode laser arrangement is able to manipulate the output from a high power laser diode array pump source using a computer-generated hologram to launch a high proportion of the pump source light into a multimode fibre portion including input reflector. A monomode fibre portion with the same fundamental-mode spot size as the multimode fibre portion is optically coupled to the multimode fibre portion and includes a reflector which reflects only the fundamental mode of the multimode and monomode fibre portions. The fundamental mode reflection forced by the monomode fibre portion provides the feedback necessary to force predominantly fundamental mode oscillation which enables stimulated emission in only the fundamental mode.

Two-stage mono-mode optical fibre laser

Filter with preselected attenuation/wavelength characteristic

Optical waveguide amplifier

A high power monomode laser arrangement is able to manipulate the output from a high power laser diode array pump source 3 using a computer-generated hologram 4 to launch a high proportion of the pump source light into a multimode fiber portion including in input reflector 6. A monomode fiber portion 2 with the same fundamental-mode spot size as the multimode fiber portion 1 is optically coupled to the multimode fiber portion and includes a reflector 5 which reflects only the fundamental mode of the multimode and monomode fiber portions. The fundamental mode reflection forced by the monomode fiber portion 2 provides the feedback necessary to force predominantly fundamental mode oscillation which enables stimulated emission in only the fundamental mode.

Semiconductor device and piezoelectric stack optical mounting assembly

Optical resonant device

Optical homodyne detection

Apparatus and method for frequency locking electromagnetic optical

Growing community of inventors

Felixstowe, United Kingdom

Richard Wyatt