The University of Southampton

Saudi Arabian Oil Company

Other

David John Richardson

Tanya Mary Monro

Francesco Poletti

Morten Ibsen

John Richard Hayes

Jonathan Hugh Vaughan Price

Neil Gregory Raphael Broderick

Sameeh Issa Batarseh

Damian Pablo San Roman Alerigi

Nikolay Ivanovich Zheludev

Lars Johan Albinsson Nilsson

Laurent LeFort

Andrew Malinowski

Radan Slavik

Periklis Petropoulos

Hans Christian Hansen Mulvad

Hesham Sakr

Shaif-ul Alam

Lin Xu

Callum Smith

Walter Belardi

Peh Chiong Teh

Ju Han Lee

Eric Rodrigue Numkam Fokoua

Joseph Kakande

Liang C Dong

Valerio Pruneri

Byoung Yoon Kim

Seok Hyun Yun

Paul William Turner

Daniel William Hewak

Natalie Wheeler

Yong Chen

Edward J Banks

Kentaro Furusawa

Francesca Parmigiani

David Oliver Culverhouse

Kentaro Furasawa

Marco Petrovich

Neil Broderick

Periklis Petropoulis

Herman Leonard Offerhaus

Rowland Sammut

Peter Jonathan Bennett

Sukhminder Dhanjal

Kevin Francis MacDonald

Yvonne Deana West

Zulfadzli Yusoff

Jianfa Zhang

Peh Choing Teh

Natalie Violet Wheeler

An optical fiber has corrugations on an outer surface to dissipate a portion of an input light beam, allowing the remaining portion of the light beam to be coupled to the optical fiber. By dissipating the portion of input light, damage to the optical fiber by uncoupled light is reduced.

Optical fiber with corrugations

A nested anti-resonant nodeless hollow core fiber (NANF) enables transmission of multi-kilowatt, continuous wave (CW) light beams operating in wavelengths between 1050 nm and 1100 nm provided by single mode lasers. Such a NANF has little loss over kilometer ranges, and can be employed in long distance subsurface applications, such as in the petroleum industry.

Nested anti-resonant nodeless optical fiber and subsurface system using the same

A method of fabricating a hollow-core photonic-bandgap fiber, comprising the steps of: providing a stack of capillaries, wherein the stack has a hollow core and the capillaries at a boundary of the core comprise a plurality of first, corner core capillaries and a plurality of second, intermediate core capillaries; applying a pressure differential between the corner core capillaries and the intermediate core capillaries, whereby a size of the corner core capillaries can be controlled in relation to the intermediate core capillaries; and reducing the stack to a fiber, wherein the fiber has a hollow core and a cladding which surrounds the core at a core boundary and comprises a lattice or network of struts and interstitial nodes which together define an array of cavities.

Hollow-core photonic bandgap fibers and methods of manufacturing the same

A hollow-core photonic bandgap fiber having a hollow core and a cladding which surrounds the core at a core boundary and comprises a lattice or network of struts and interstitial nodes which together define an array of cavities, wherein a ratio between a difference in a length of a longest and shortest pitch spacing of the nodes at the core boundary to an average pitch spacing at the core boundary is less than about 0.3.

First and second coherent light beams of the same wavelength are propagated in opposite directions to interact on a sub-wavelength thickness metallic metamaterial layer which is structured with a periodicity such that there is a resonance matched to the wavelength of the coherent beams. The first beam is then able to modulate the intensity of the second beam by modulating the phase and/or intensity of the first beam. The interference of the counter- propagating beams can eliminate or substantially reduce Joule loss of light energy in the metamaterial layer or, on the contrary, can lead to a near total absorption of light, depending on the mutual phase and/or intensity of the interacting beams. A modulation is thus provided without using a non-linear effect.

Optical devices, systems and methods

An optical transmitter, comprising: a master laser device for generating a master signal; one or more slave laser devices, injected with the master signal such that signals generated by the one or more slave laser devices are phase-locked with the master signal; an input for receiving one or more data streams to be transmitted, the one or more data streams being used to modulate respectively the one or more slave laser devices, such that each signal generated by the one or more slave laser devices respectively comprises a modulated part and a carrier part; and an interfering arrangement, for destructively interfering the signals generated by the one or more slave laser devices with a signal derived from the master signal, so as to generate an output signal in which the carrier part is at least partially cancelled. In embodiments, the transmitter comprises multiple slave laser devices, whose outputs can be coherently multiplexed together to generate multiple-bit output signals.

Optical transmitter

An optical regenerator for regenerating a multi-level phase encoded signal. A first non-linear medium (HNLF) generates a comb of frequency harmonics from the signal under the action of a coherent pump, each component bearing the phase encoded data. A filter selects the first and (M&#x2212;1)th order components. The filtered signal is then input to a second non-linear medium (HNLF) where a further pump is applied, to coherently add the first and (M&#x2212;1)th order components and regenerate the signal by reducing phase noise.

Optical signal processing

A source of pulses of coherent radiation at a wavelength of approximately 1 &#x3bc;m, comprises a pump source for producing pump light; a laser cavity comprising an Yb-doped gain medium arranged to receive the pump light, the laser cavity being modelocked to generate laser pulses at a defined repetition rate; a pulse detector arranged to generate a pulse selection signal indicative of the repetition rate; a pulse selector arranged to reduce the repetition rate of the laser pulses responsive to the pulse selection signal from the pulse detector by passing only selected ones of the laser pulses; and at least one optical amplifier for amplifying the laser pulses of reduced repetition rate. The at least one optical amplifier can be configured for chirped or parabolic pulse amplification.

Pulsed light sources

To overcome problems of fabricating conventional core-clad optical fibre from non-silica based (compound) glass, it is proposed to fabricate non-silica based (compound) glass optical fibre as holey fibre i.e. one contining Longitudinal holes in the cladding. This removes the conventional problems associated with mismatch of the physical properties of the core and clad compound glasses, since a holey fibre can be made of a single glass composition. With a holey fibre, it is not necessary to have different glasses for the core and cladding, since the necessary refractive index modulation between core and cladding is provided by the microstructure of the clad, i.e. its holes, rather than by a difference in materials properties between the clad and core glasses. Specifically, the conventional thermal mismatch problems between core and clad are circumvented. A variety of fibre types can be fabricated from non-silica based (compounds) glasses, for example: single-mode fibre; photonic band gap fibre; highly non-linear fibre; fibre with photosensitivity written gratings and other refractive index profile structures; and rare-earth doped fibres (e.g. Er, Nd, Pr) to provide gain media for fibre amplifiers and lasers.

Holey optical fibres of non-silica based glass

An optical fibre device based on the Raman effect comprises a first optical source to provide light at a first wavelength, and a holey optical fibre which receives the light from the first optical source such that optical gain or loss is provided at a second wavelength by the effect of Raman scattering within the fibre. For optical gain, the second wavelength is longer than the first wavelength, and the device can be operated as an amplifier, or as a laser if optical feedback is provided. For optical loss, the second wavelength is shorter than the first, and the device may be used as an optical modulator. The fibre may be fabricated from pure silica, although other undoped or doped materials may alternatively be used to tailor properties of the fibre such as gain spectrum, bandwidth, power handling capability and mode propagation.

Optical fibre-based devices utilising the Raman effect

Apparatus for providing timing jitter tolerant optical modulation of a first signal by a second signal, the first signal having a first wavelength, the second signal including a plurality of second signal pulses having a second pulse shape and a second wavelength. The apparatus includes a first signal input port, a second signal input port, a coupler, a grating and a non-linear optical device. The apparatus is configured to direct the second signal at the second signal input port to the non-linear optical device via the coupler and the grating, and to direct the first signal at the first signal input port to the non-linear optical device. The grating is a superstructured fibre Bragg grating that converts the second signal pulses into intermediary pulses each having an intermediary pulse shape. The intermediary pulse shape is such that it provides a switching window within the non-linear optical device.

Apparatus for providing timing jitter tolerant optical modulation of a first signal by a second signal

An optical fiber structure having a holey fiber arranged in a holey outer support structure made up of holey tubes encased in a thin walled outer jacket. The holey fiber may have a solid core surrounded by a holey cladding having a plurality of rings of holes. With the invention it is possible to produce robust, coated and jacketed fibers with microstructured core features of micrometer size relatively easily using existing fiber fabrication technology. This improvement is a result of the outer holey structure which reduces the thermal mass of the supporting structure and makes it possible to reliably and controllably retain small hole features during the fiber fabrication process.

Holey optical fibres

A source of pulses of coherent radiation at a wavelength of approximately 1 &#x3bc;m, comprises a pump source for producing pump light, a laser cavity comprising an Yb-doped gain medium arranged to receive the pump light, the laser cavity being modelocked to generate laser pulses at a defined repetition rate; a pulse detector arranged to generate a pulse selection signal indicative of the repetition rate; a pulse selector arranged to reduce the repetition rate of the laser pulses responsive to the pulse selection signal from the pulse detector by passing only selected ones of the laser pulses; and at least one optical amplifier for amplifying the laser pulses of reduced repetition rate. The at least one optical amplifier can be configured for chirped or parabolic pulse amplification.

A broadband laser source comprising: a resonant cavity () containing a medium () which emits optical energy () in a continuum of wavelengths in response to application of pump energy () to the medium (); a source of pump energy () for producing said optical energy (); a frequency shifter () within the resonant cavity (); and a tuneable spectral filter () within the resonant cavity (), and the apparatus being such that in use the tuneable spectral filter () has a peak wavelength which is repeatedly swept in a substantially resonant fashion over a wavelength range equal to, or a fraction of, a linewidth of the broadband source such that the rate of change of the peak wavelength of the tuneable spectral filter () is substantially equal to the rate of change of the frequency of the optical energy () as it is frequency shifted within the resonant cavity () by the frequency shifter ().

Broadband laser source

A source of optical pulses, comprises an optical source operable to generate ultrashort optical pulses at a first wavelength; and an optical fiber amplifier comprising an optical fiber having a core containing a dopant to provide optical gain at the first wavelength and anomalous dispersion over a wavelength range including the first wavelength and a second wavelength. The optical fiber receives the ultrashort optical pulses, amplifies the ultrashort optical pulses, and alters the wavelength of the ultrashort optical pulses to at least the second wavelength by the soliton-self-frequency shifting effect. Microstructured and/or tapered fibers can be used to provide the required dispersion characteristics. Pulses can be generated in one of three spectral regimes&mdash;monocolor solitons, multicolor solitons and continuous broadband spectra by adjusting the energy of the optical pulses, and tunability can be achieved by varying the power of pump light provided to the amplifier.

Sources of, and methods for generating, optical pulses

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Southampton, United Kingdom

David John Richardson