Abstract: A method of manufacturing active optical fibers comprising preparing a preform and then drawing a fiber from the preform, wherein the method consists in using a preform having a doped peripheral outer zone, said zone being intended to constitute the outer cladding of the optical fiber, the doping of the peripheral zone giving it a refractive index greater than that of the optical cladding, and giving it a difference in softening temperature relative to that of the core of the optical fiber which is less than the difference that would exist if the outer zone were not doped.

Abstract: A device for displaying the core (C) of an optical fiber (F) in two directions that are transverse to the fiber (F) includes two light sources illuminating the fiber. Each source emits a beam of light. The beams have different directions D.sub.1 and D.sub.2. The directions lie in a plane that is orthogonal to the longitudinal axis (X) of the fiber (F). An objective lens (L.sub.3, L.sub.4), reception and display components (2, 3) are employed and receive and display images of the fiber (F) produced by the beams. The objective lens is focused in a plane (P) that intercepts the beams from the fiber (F) inside the fiber (F). The angle (.alpha..sub.1, .alpha..sub.2) between either of the directions (D.sub.1, D.sub.2) and the focal axis (Y) of the objective lens (L.sub.3, L.sub.4) is such that the objective lens (L.sub.3, L.sub.4) directly receives the two beams from the fiber (F) with sufficient light intensity to enable the display component to operate.

Abstract: Apparatus for treating the surface of a body by corona discharge, the apparatus comprising:a reaction enclosure through which said body to be treated can run along a "through" axis;an electrode raised to a "treatment" potential;a counter-electrode raised to a potential that is lower in absolute value than the potential of said electrode, said counter-electrode surrounding said through axis and said electrode and said counter-electrode together being disposed so as to define a "plasma-generating" zone in the vicinity of said through axis and in which said corona discharge takes place; andat least one passage formed in said enclosure to feed a plasma-generating reagent gas for treatment purposes;wherein said electrode is provided with a plurality of portions having small radius of curvature, i.e.

Abstract: A micro-welder for optical fibers includes a stand having a central support surrounded by two lateral supports or beams. The beams are suitable for moving under drive from a bending movement about respective X-axes. The stand also supports a device for securing optical fibers on the beams and a device for accurately guiding the fibers on the central support. A low accuracy first displacement device is adapted to displace the beams to bring the fibers into end-to-end contact with each other by relative translation movement along their longitudinal Z-axis which is orthogonal to the X-axes. A high accuracy second displacement device is adapted for moving the beams to drive the fibers with accurate relative translation movements along the Z-axis. Two welding electrodes are provided and an optical device which includes a microscope for observing the ends of said optical fibers.

Abstract: Apparatus for detecting irregularities in the diameter of a filament has a small light source placed at the focus of an objective lens system. A horizontal slot constitutes a diaphragm for the objective lens system. A first optical system forms an image of the slot in a plane in which the filament runs past. Detectors detect the beam intercepted by the filament. An optical splitting system (P1) is interposed in the path of the beam (A), downstream of the slot (3) and upstream of the filament (5). The system is designed to form two sharp images (3', 3") of the slot (3) in a plane (4). The detectors are two oppositely-connected detectors (D1, D2) each receiving a respective beam (C, C') intercepted by the filament (5).

Abstract: A cylindrical piece of glass (4) is subjected to heating passes on a glassmaker's lathe. Possible opto-geometrical defects of said piece of glass are detected and measured and then said defects are corrected by machining the outside surface thereof during a correction pass performed on the same glassmaker's lathe.

Abstract: A device for use in on-site conditions to obtain a section plane which reproducibly makes an angle of 5.degree., for example, relative to the axis of an optical fiber. The device includes a clamp for holding the fiber at a first point, a rotary clamp for holding the fiber at a second point and for twisting it about the axis of the fiber. The device further includes two jaws for holding the fiber at a third point after it has been twisted by means of the rotary clamp. A convex anvil subjects the fiber to tension after it has been twisted. A diamond cutter is employed for cleaving the fiber. The invention is applicable to providing an optical fiber cutting tool suitable for cutting the fiber obliquely on the worksite.

Abstract: The invention relates to a method of making multi-ferrules. It provides a method of making multi-ferrules from a vitreous material, the multi-ferrules having a series of cylindrical channels with parallel axes.

Abstract: 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.

Abstract: A cutting tool has four main parts hinged about two axes parallel to the direction of the fiber to but cut. Progressively increasing hand pressure applied by a user enables certain operations to be performed automatically and in succession. Two pairs of jaws are clamped to prevent the fiber from moving between two axially spaced points. The fiber is put under tension by applying an anvil thereagainst, and cleaving is initiated by applying a diamond chisel against the fiber, with cleaving being completed by the tension set up by the anvil. Three springs exert different force couples, thereby determining the order in which these operations occur.

Abstract: The integrated optical component having a glass substrate including integrated optical waveguides wherein the substrate further includes longitudinal grooves at opposite ends of the central portion thereof, which longitudinal grooves are obtained by machining, using the terminal portions of the waveguides extending beyond said central portion as marks for determining the line of machining, together with two transverse grooves on either side of the central portion of the substrate, with the two grooves being separated by a rib whose height is rectified so as to support each fiber to be connected to a waveguide that opens on the same side as the rib.

Abstract: The device includes a first jointing component for joining two fibers to two integrated optic outlet waveguides in the glass substrate, these two fibers are mounted touching one another to constitute a sheet which is itself bonded between two plates of glass, and the spacing of the two corresponding waveguides is equal to the diameter of the fibers, said first jointing component together with its fibers and a second jointing component together with another fiber at the inlet waveguide being bonded against said substrate.