Alcatel

Avanex Corporation

Alcatel Alsthom Compagnie Generale D'electricite

Alcatel N.v.

Draka Comteq B.v.

Alcatel Fibres Optiques

Alcatel Submarcom

Alcatel Optronics

Avonex Corporation

Isabelle Riant

Pierre Sansonetti

Carlos Luis De Barros

Marianne Molina

Lionel Provost

Xavier Bonnet

Jose Chesnoy

Jean-Jacques Guerin

Val&eacute;rie Girardon

Fatima Bakhti

Hedi Labidi

Alain Fradet

Xavier Andrieu

Christian Belouet

Jean-Michel Gabriagues

Laurent Gasca

Denis Cottevieille

Michel Jurczyszyn

Pierre Doussiere

Laurent Berthelot

Francedillaois Gonthier

Hervé Lefebvre

Christelle Leclere

Hervé Loury

Martine Tessier

Jean Jacques Guerin

V&eacute;ronique Verdrager

Valérie Girardon

David Macia

Jean Guillon

An optical device (D) is dedicated to the transformation of the propagation mode of optical signals. This device comprises at least a first mode converter () that is supplied with signals that are propagated in a first guided mode and that delivers the signals in a multimode fibre () partly in the first guided mode and partly in a second guided more of a higher order that the first. The multimode fibre () comprises at least first passive filtering means (R) which have the task of converting the first guided mode into at least one dissipative cladding mode in order to prevent or limit the propagation of the signals in this first guided mode while at the same time authorising the propagation of the signals having the second guided mode in the multimode fibre ().

Suppresson of undesirable signal propagation mode(s) downstream of mode converter

The present invention consists in an optical device comprising an optical component and an optical medium with different refractive indices, said optical component being at least partly immersed in said optical medium, which device is characterized in that said optical medium contains a salt that is in the liquid state in the range of temperatures at which said optical component is used and stored, i.e. in a range of temperatures generally from &#x2212;40&#xb0; C. to +200&#xb0; C. The optical component may in particular be a Bragg long-period grating (LPG) or a photonic crystal fiber.

Optical device comprising an optical component and an optical medium with different refractive indices

A tunable optical filter comprising an index grating produced in a waveguide defining a longitudinal direction of propagation of an incident optical signal, said grating being defined by a plurality of optical parameters, is characterized in that the optical guide contains semiconductor nanoparticles and in that the index grating is made up of a refractive index variation in the guide that is at least partly induced by a Kerr effect linked to the 3order dielectric susceptibility (&#x3c7;) of said nanoparticles, at least one of said parameters of said index grating being modified by application of an optical control signal coupled into the guide and propagating longitudinally in said guide.

Reconfigurable optical filter

An optical filter comprises a first mode converter converting an incident light signal propagating in an incident mode into a signal propagating in a propagation mode LPnm of order higher than that of said incident mode; a second mode converter converting the light signal of higher propagation order LPnm into a signal propagating in the incident propagation mode; and a slanted Bragg grating disposed between said first and second mode converters and adapted to couple the higher propagation order light signal LPnm in back-propagation into said incident mode. The filter is applicable to flattening gain and to multiplexing DWDM signals.

Optical filter

The invention concerns a tunable filter comprising an optical fiber incorporating a Bragg grating on a portion of the fiber. Said fiber portion is coated with a material retained within a confined space and adapted to exert pressure on said Bragg grating to compress said portion of fiber radially and to stretch it longitudinally.

Tunable filter consisting of an optical fiber, and a corresponding method

The invention is related to an optical waveguide device comprising

Optical waveguide and method for creating an asymmetrical optical filter device

The invention relates to an optical fiber presenting a core, cladding, and a grating written by irradiation and coupling at least one light mode into the cladding so that it is dissipated therein. The invention proposes causing the mean index to vary progressively along the grating, at least at the ends of the grating. The progressive variation in mean index or in the amplitude of index modulation for writing the grating serves to limit insertion losses to the filter formed by the grating. Analogously, in a written-in grating, the invention provides the equivalent of progressively varying the core size of the fiber for interconnecting two optical fibers presenting different core diameters. The invention is applicable in particular to gain-equalizing filters in WDM transmission systems.

Reducing insertion losses of a written in grating with mode coupling in the cladding

An optical device (D) is dedicated to transforming the propagation mode of optical signals. The device comprises mode transformation means () associated with a multimode fiber () and comprising first and second mode converters (and) coupled to each other by a multimode fiber portion () of selected length (L). The first converter () is fed with signals propagating in a first mode and it delivers the signals to the fiber portion () in part in the first mode and in part in a second mode of order higher than the first, and the second converter () is arranged to cause the signals in the first and second modes to interfere so that on outlet therefrom they present a selected spectral spacing.

Device and a method for transforming signal propagation mode by interference

An optical filter composed of a concatenation of elementary filters consisting of chirped slanted Bragg gratings written on a continuous portion of an optical waveguide, characterized in that the various gratings in the concatenation have the same angle, identical lengths and a linear chirp.

Apodised complex filter

An optical mode converter comprising an optical guide able to transmit an optical signal in at least one guided mode, characterised in that the optical guide comprises a photosensitive zone inducing a specific index profile along a section of the guide, the said index profile simultaneously defining a longitudinal adiabatic transition and a transverse distribution of the guided mode or modes so as to deconfine the fundamental mode and to maximise the overlap with a higher-order mode.

Optical mode converter

The present invention relates to the field of optical fiber telecommunications. More specifically, the subject of the invention is a slanted Bragg grating optical fiber and a process for manufacturing such a fiber. The slanted Bragg grating optical fiber of longitudinal axis Z has slanted Bragg gratings photowritten in said fiber and having refractive index modulations along said axis Z, inclined at a same writing angle with respect to a normal plane to said axis Z and defining planes called writing planes forming the same angle than the writing angle with said normal plane, each writing plane forming with others writing planes specific angles called angles of rotation about said axis Z.

Slanted Bragg grating optical fiber and process for manufacturing such a fiber

A tuneable optical fibre comprising a long-period Bragg grating () written in a portion of an optical waveguide () comprising a core and an optical cladding (), characterised in that the portion of the waveguide comprising the grating () is at least partially immersed in an external environment consisting of two distinct sections, a first section () whose refractive index is higher than that of the optical cladding () and a second section () whose refractive index is lower than that of the optical cladding (), the long-period grating being at least partially immersed in one of the said sections so as to almost independently tune the wavelength and/or the contrast of the spectral response of the filter.

Dynamic gain equalizing filter

An optical filter comprising a slanted Bragg grating inscribed in an optical fiber portion comprising a core having a refractive index nand a radius Rand a cladding having an average refractive index nlower than nand a radius R, the core and the cladding of the fiber being doped with a photosensitive dopant in the fiber portion comprising the Bragg grating, which filter is characterized in that, in the fiber portion comprising the Bragg grating, the photosensitivity of the cladding is greater than the photosensitivity of the core and the cladding includes an index step area having a refractive index ngreater than nand less than n, said index step area having a width L defined by an inside radius Rgreater than or equal to the radius Rof the core and an outside radius Rless than or equal to the radius Rof the cladding.

Fibre grating optical waveguide device

The present invention proposes optical fiber equipment having a Bragg grating tunable by a piezoelectric actuator, the equipment comprising an optical fiber, a Bragg grating photoinduced in said fiber, a support for supporting said fiber and comprising two uprights at opposite ends of said Bragg grating, each upright having a first holding element for holding said fiber, and a piezoelectric actuator held via its ends between the two uprights, said actuator being longitudinally prestressed in compression between said uprights.

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Orsay, France

Isabelle Riant