Alcatel Fibres Optiques

Alcatel N.v.

Compagnie Generale D'electricite

Alcatel Cable Interface

Jean-Yves Boniort

Claude Brehm

Andre Tardy

Pierre Sansonetti

Jose Chesnoy

Georges Roussy

Bruno Lavigne

Lionel Vandenbulcke

Pascale Nouchi

Roland Hakoun

Jacques Auge

Jacques Leboucq

Bertrand Joly

Jacques Com-Nougue

Jean-Louis Brisset

Pierre Lerner

Denis Robion

Yves Floury

A method of manufacturing a multi-core optical fiber, the method including assembling together a plurality of substantially identical single-core optical fiber preforms (2', 2'), referred to as 'single-core preforms', each of which includes a core bar (3) surrounded by a layer of optical cladding (4), so as to form a 'multi-core preform' (10) and drawing down the multi-core preform (10) so as to obtain the multi-core optical fiber. The assembly step includes securing the single-core preforms (2', 2') to one another by fusing them over their entire lengths or over portions thereof along their tangential lines of contact (T), without inserting the multi-core preform (10) into a holding tube. A vacuum is maintained in the preform during the drawing step, the vacuum being formed before or during the drawing step.

Method of manufacturing a multi-core optical fiber

A method of manufacturing a multi-core optical fiber, the method including assembling together a plurality of substantially identical polished single-core optical fiber preforms (2', 2'), referred to as 'single-core preforms', each of which includes a core bar (3) surrounded by a layer of optical cladding (4), so as to form a 'multi-core preform' (10), and drawing down the multi-core preform (10) so as to obtain the multi-core optical fiber. The assembly step includes securing the single-core preforms (2', 2') to one another by fusing them over their entire lengths or over portions thereof along their tangential lines of contact (T), without inserting the multi-core preform (10) into a holding tube. A vacuum is maintained in the preform during the drawing step, the vacuum being formed before or during the drawing step.

Method of applying an amorphous boron-based protective coating to an

Optical fiber coated with an amorphous boron protective layer, and a

Monomode optical fiber

The multiferrule for connecting optical fibers together has a series of internal capillary channels of transverse dimensions that are defined to leave substantial clearance for the fibers, at least in the two end portions of the channels where they open out into two end faces of the multiferrule. The multiferrule further includes middle necking in which the corresponding middle portions of the channels have their transverse dimensions reduced so as to leave only minimal clearance for the fibers, to enable them to be put into contact and connected together directly in this location. The multiferrule is applicable to making an optical fiber connector.

Multiferrule for connecting optical fibers together, a connector

Apparatus for heating a silica optical fiber in a fiber-drawing installation. The apparatus is disposed at the outlet of a fiber-drawing oven to raise the optical fiber to a temperature greater than 1000.degree. C. The apparatus is constituted by a microwave generator coupled to a resonant cavity formed by a helically-wound metal wire helix fixed at opposite ends to two short circuit metal plates respectively, with the optical fiber running substantially along the axis of the helix and the helix concentric about the running fiber.

Method and apparatus for heating a silica optical fiber in a

Apparatus for measuring continuously and without contact the thickness of a thin conducting layer on a running insulating support of the fiber or tape kind, wherein the apparatus includes: a microwave generator associated by coupling means to a resonant cavity comprising a metal wire in the form of a helix which is fixed at its ends to two metal plates, said insulating support being suitable for running substantially along the axis of said helix; and means for coupling said cavity to a detection device for detecting the transmission factor of said cavity, which factor is directly a function of said thickness, said measurement being performed at constant frequency.

Microwave measuring apparatus for continuously and without contact

Apparatus for treating the surface of a body by corona discharge, the apparatus comprising:

Apparatus for surface treatment by corona discharge

Optical fiber suitable for use in optical time domain reflectometry and method of manufacturing the fiber. The method of manufacturing the optical fiber suitable for use in optical time domain reflectometry includes, during drawing of the fiber (2), a thin continuous coating is deposited on the fiber. A part of the coating is thereafter removably ablated in the form of a helix (15) coaxial with the fiber by rotating a laser beam (17) in a plane orthogonal to the axis simultaneously with axial movement of the fiber.

Optical fiber suitable for use in optical time domain reflectometry and

An optical fiber (F) is pulled by a capstan (6) from a silica preform (1) whose bottom end (20) is softened in an oven (2). After cooling, said fiber is coated with an organic protective coating by means of a coating device (4). According to the invention, the surface of the fiber is reheated under tension by means of a torch (14) upstream from the covering device. Tension stresses in the softened surface layer are therefore relaxed. Cooling, followed by the fiber-drawing tension being removed after the capstan (6) cause said surface layer to be put under permanent compression, thereby reducing the risk of the fiber breaking. The invention is applicable to manufacturing fibers having improved characteristics.

Method of manufacturing a high mechanical strength optical fiber by

The invention relates to a high-frequency furnace whose wall is formed by superposed wall-forming members. This furnace includes in particular an inner tubular wall comprising a zirconia tube (38), an alumina washer (39) laid on the zirconia tube and a silica tube (40) laid on the washer. There is a large groove (41) in a top plate (37) to accommodate the silica tube (40). The furnace also includes an outer tube (36) of silica. This structure makes it possible to accommodate differential expansion of the zirconia and the silica in two separate steps. The axial difference is accommodated at the groove (41) while the radial difference is accomodated at the washer (39). Leakage of inert gas pumped into the chamber during operation can then be maintained within acceptable limits throughout the temperature range. Application to the production of optical fibers.

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Limours, France

Jean-Yves Boniort