Abstract: A multi-mode optical waveguide fiber including a central core region having an outer radius surrounded by an inner cladding region having an outer radius, the inner cladding region having a lower index of refraction than the central core region, wherein both the central core and inner cladding regions are doped with fluorine, wherein the refractive index profile of the central core region is of the gradient index type and the central core region in the range of r?[0-ra] comprises germanium at a maximum concentration within the range of 0.5 percent by weight to 4.0 percent by weight taken at a given radius, wherein said fiber has an Overfilled Modal Bandwidth >500 MHz·km at a wavelength of 850 nm and 1300 nm, according to IEC 60793-2-10.

Abstract: Disclosed is an optical fiber that includes a central core that is suitable for transmitting and amplifying an optical signal and an inner optical cladding that is suitable for confining the optical signal transmitted within the central core. The central core is formed from a core matrix that contains silica-based nanoparticles doped with at least one rare earth element. The disclosed optical fiber can be used with limited optical losses even in an environment with strong ionizing radiation.

Abstract: An optical fiber preform comprises a primary preform that includes at least one inner cladding and a central core deposited inside a fluorine doped silica tube. The fluorine doped silica tube has a cross section area that is no more than about 15 percent smaller than the cross section area of the primary preform. The optical fiber preform has a large capacity, may be manufactured at reduced cost, and may be drawn to produce an optical fiber having reduced transmission losses.

Abstract: A method for manufacturing an optical fiber preform includes the steps of depositing an inner cladding and a central core inside a fluorine doped silica tube and thereafter collapsing the silica tube to form a primary preform. The fluorine doped silica tube has a cross section area that is no more than about 15 percent smaller than the cross section area of the resulting primary preform. The present method facilitates reduced-cost manufacturing of a high-capacity optical fiber preform, which may be drawn to produce an optical fiber having reduced transmission losses.

Abstract: A multi-mode optical waveguide fiber including a central core region having an outer radius surrounded by an inner cladding region having an outer radius, the inner cladding region having a lower index of refraction than the central core region, wherein both the central core and inner cladding regions are doped with fluorine, wherein the refractive index profile of the central core region is of the gradient index type and the central core region in the range of r?[0-ra] comprises germanium at a maximum concentration within the range of 0.5 percent by weight to 4.0 percent by weight taken at a given radius, wherein said fiber has an Overfilled Modal Bandwidth >500 MHz·km at a wavelength of 850 nm and 1300 nm, according to IEC 60793-2-10.

Abstract: A dispersion-shifted optical fiber (NZDSF) includes a central core (r1, Dn1), an inner cladding having at least three zones with a first intermediate cladding zone (r2, Dn2), a second ring zone (r3, Dn3) and a third buried trench zone (Wtr, Dnt). The buried trench zone has an index difference (Dnt) with the optical cladding between ?5·10?3 and ?15·10?3 and has a width (Wtr) between 2.5 ?m and 5.5 ?m. The present optical fiber, at a wavelength of 1550 nm, has reduced Rayleigh scattering losses of less than 0.164 dB/km, with limited bending losses.

Abstract: A treatment method for an optical fibre including the steps of exposing the fibre to an atmosphere containing deuterium at a given temperature, concentration and pressure, measuring the attenuation in the fibre as a function of time at least one wavelength, during the exposure of the fibre to an atmosphere containing deuterium, identifying an attenuation maximum after an exposure duration, and stopping the exposure of the fibre to the atmosphere containing deuterium when said duration has elapsed.

Abstract: A method for manufacturing an optical fiber preform includes the steps of depositing an inner cladding and a central core inside a fluorine doped silica tube and thereafter collapsing the silica tube to form a primary preform. The fluorine doped silica tube has a cross section area that is no more than about 15 percent smaller than the cross section area of the resulting primary preform. The present method facilitates reduced-cost manufacturing of a high-capacity optical fiber preform, which may be drawn to produce an optical fiber having reduced transmission losses.

Abstract: An optical fiber preform comprises a primary preform that includes at least one inner cladding and a central core deposited inside a fluorine doped silica tube. The fluorine doped silica tube has a cross section area that is no more than about 15 percent smaller than the cross section area of the primary preform. The optical fiber preform has a large capacity, may be manufactured at reduced cost, and may be drawn to produce an optical fiber having reduced transmission losses.

Abstract: Disclosed is an optical fiber that includes a central core that is suitable for transmitting and amplifying an optical signal and an inner optical cladding that is suitable for confining the optical signal transmitted within the central core. The central core is formed from a core matrix that contains silica-based nanoparticles doped with at least one rare earth element. The disclosed optical fiber can be used with limited optical losses even in an environment with strong ionizing radiation.

Abstract: A method for manufacturing a final optical fiber preform via overcladding of a primary preform having a cross section area is disclosed. The method includes at least one manufacturing step of the primary preform by deposit of an inner cladding and of a central core inside a tube of fluorine-doped silica, the tube being chosen such that it has a cross section area that is maximally about 15% less than the cross section area of the primary preform. With the method of the invention it is possible to manufacture a preform of large capacity at reduced cost which allows the drawing of an optical fiber having reduced transmission losses.

Abstract: A single mode optical transmission fiber comprises a depressed core having at least 0.41 weight percent fluorine and an index difference (|?n1|) with pure silica greater than 1.5×10?3, a depressed cladding having at least 1.2 weight percent fluorine and an index difference (|?n2|) with pure silica greater than 4.5×10?3 and an index difference (|?n2|?|?n1|) with the depressed core greater than or equal to 3×10?3.

Abstract: A dispersion-shifted optical fiber (NZDSF) includes a central core (r1, Dn1), an inner cladding having at least three zones with a first intermediate cladding zone (r2, Dn2), a second ring zone (r3, Dn3) and a third buried trench zone (Wtr, Dnt). The buried trench zone has an index difference (Dnt) with the optical cladding between ?5·10?3 and ?15·10?3 and has a width (Wtr) between 2.5 ?m and 5.5 ?m. The present optical fiber, at a wavelength of 1550 nm, has reduced Rayleigh scattering losses of less than 0.164 dB/km, with limited bending losses.

Abstract: A single mode optical transmission fiber comprises a depressed core having at least 0.41 weight percent fluorine and an index difference (|?n1|) with pure silica greater than 1.5×10?3, a depressed cladding having at least 1.2 weight percent fluorine and an index difference (|?n2|) with pure silica greater than 4.5×10?3 and an index difference (|?n2|?|?n1|) with the depressed core greater than or equal to 3×10?3.

Abstract: A single mode optical transmission fiber comprises a depressed core having at least 0.41 weight percent fluorine and an index difference (|?n1|) with pure silica greater than 1.5×10?3, a depressed cladding having at least 1.2 weight percent fluorine and an index difference (|?n2|) with pure silica greater than 4.5×10?3 and an index difference (|?n2|?|?n1|) with the depressed core greater than or equal to 3×10?3.

Abstract: A single mode optical transmission fiber comprises a depressed core having at least 0.41 weight percent fluorine and an index difference (|?n1|) with pure silica greater than 1.5×10?3, a depressed cladding having at least 1.2 weight percent fluorine and an index difference (|?n2|) with pure silica greater than 4.5×10?3 and an index difference (|?n2|?|?n1|) with the depressed core greater than or equal to 3×10?3.

Abstract: A method for manufacturing a final optical fiber preform via overcladding of a primary preform having a cross section area is disclosed. The method includes at least one manufacturing step of the primary preform by deposit of an inner cladding and of a central core inside a tube of fluorine-doped silica, the tube being chosen such that it has a cross section area that is maximally about 15% less than the cross section area of the primary preform. With the method of the invention it is possible to manufacture a preform of large capacity at reduced cost which allows the drawing of an optical fiber having reduced transmission losses.