Abstract: A repair line for repairing a closure defect in a metal tube containing at least one transmission optical fiber which includes a repair station having a tube conditioning system for bending and tensioning a portion of the tube including the defect and a laser for welding point by point along the defect with the minimum heat input at each point.

Abstract: An optical fiber cable connection organizer device includes a support assembly with lateral accessways for the fibers of the cables, an arrangement for holding splices between the fibers and an arrangement for stowing a surplus length of the jointed fibers. It further includes two sets of magazines for stowing additional slack in the fibers from the two cables. Applications include submarine optical fiber cable joint boxes.

Abstract: The unit for protecting the inside of a metal tube containing at least one optical fiber against overheating limits the extent to which fibers inserted by an auxiliary tube and filler gel overheat level with the laser welding that closes the metal tube. The unit including a thermal diffuser interposed between the auxiliary tube for inserting fibers and the closure zone that is defined on the metal tube. The invention is applicable to making an underwater optical cable.

Abstract: A method of injecting a filler in controlled manner into a protective tube for protecting optical fibers, the method consisting in regulating the delivery rate of the filler being injected as the closed tube advances. In the method, the delivery rate is regulated by detecting the position of the front of the filler contained in the protective tube relative to at least one detection point on the line for advancing the closed protective tube.

Abstract: The invention provides a Fabry-Perot filter for guided light, the filter comprising two Bragg gratings that follow each other along a common light guide, a gap being left between the two gratings, wherein the two gratings have respective different lengths. The invention is particularly applicable to optical fiber telecommunications systems.

Abstract: A method of repairing a closure defect in a metal tube containing at least one transmission optical fiber entails bending and tensioning a portion of the tube including the defect and laser welding point by point along the defect within the bent portion with the minimun heat input at each point.

Abstract: A single-mode optical waveguide comprises an optical core and a cladding surrounding the optical core having a predetermined refractive index. The core comprises a central area that has a refractive index lower than the predetermined refractive index and annular area around the central area that has a refractive index higher than the predetermined refractive index. Between the peripheral annular area and the cladding is at least one composite annular area made up of two successive annular areas respectively having refractive indices lower than and higher than the predetermined refractive index.

Abstract: A system for transmission over a repeaterless optical fiber line between an emitter and a receiver terminal, the system being of the type implementing remote optical amplification and local optical amplification on reception. The remote optical amplification consists in sending a pump beam from the receiver terminal towards at least one remote section of doped fiber situated upstream in said optical fiber line, said receiver terminal including, in particular, pumping means enabling said pump beam to be generated and enabling it to be injected into said optical fiber line. The terminal also includes means for performing said local optical amplification. According to the invention, said means for implementing local optical amplification are constituted by at least one local section of doped fiber situated within said receiver terminal between said pumping means and said optical fiber line.