Abstract: An improved optical fiber achieves both reduced bending and microbending losses, as well as a much higher Brillouin threshold, as compared to standard transmission fibers. The optical fiber comprises a core including at least two dopants and having a refractive index difference ?n1 with an outer optical cladding, a first inner cladding having a refractive index difference ?n2 with the outer cladding, and a depressed, second inner cladding having a refractive index difference ?n3 with the outer cladding of less than ?3×10?3. The radial concentration of at least one of the core dopants varies continuously over the entire core region of the optical fiber.

Abstract: Disclosed is an optical transmission fiber having reduced bending and microbending losses that is commercially usable in FTTH or FTTC transmission systems.

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: An improved optical fiber achieves both reduced bending and microbending losses, as well as a much higher Brillouin threshold, as compared to standard transmission fibers. The optical fiber comprises a core including at least two dopants and having a refractive index difference ?n1 with an outer optical cladding, a first inner cladding having a refractive index difference ?n2 with the outer cladding, and a depressed, second inner cladding having a refractive index difference ?n3 with the outer cladding of less than ?3×10?3. The radial concentration of at least one of the core dopants varies continuously over the entire core region of the optical fiber.

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 transmission fibre with optical amplification, comprising a core and a cladding. The core material is doped with a first dopant of a material having a higher index of refraction than the material of the cladding and with a second dopant of a material that converts pump energy in the form of light having a first wavelength into light having a second wavelength. The concentration of the second dopant within the core increases in radial direction in proportion to the distance to the centre of the core. The core material is preferably doped with a third dopant for compensating the variation in the refractive index caused by the second dopant. The cladding may comprise a cladding layer surrounding the core provided with a fourth and a fifth dopant for signal amplification and refractive index compensation, respectively, in the cladding layer. The dopants have been selected to enable amplification, using the Raman effect or stimulated emission.

Abstract: The invention relates to an access network for exchanging communication signals between a transit network and at least one communication medium of a user. The communication medium is operatively connected to an exchange by means of an optical fibre connection for exchanging the communication signals, and the exchange is connected to the transit network. The fibre connection comprises at least one multimode fibre, which is bent over at least one first part of its length, in such a manner that the fibre comprises at least one complete winding in the first part thereof mainly for maintaining one or more modes of the communication signals into the fibre. Said modes have been selected from a group comprising the ground mode and one or more lower modes near the ground mode.

Abstract: An improved optical fiber achieves both reduced bending and microbending losses, as well as a much higher Brillouin threshold, as compared to standard transmission fibers. The optical fiber comprises a core including at least two dopants and having a refractive index difference ?n1 with an outer optical cladding, a first inner cladding having a refractive index difference ?n2 with the outer cladding, and a depressed, second inner cladding having a refractive index difference ?n3 with the outer cladding of less than ?3×10?3. The radial concentration of at least one of the core dopants varies continuously over the entire core region of the optical fiber.

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: Disclosed is an optical transmission fiber having reduced bending and microbending losses that is commercially usable in FTTH or FTTC transmission systems.

Abstract: An optical transmission fiber comprises a central core having an index difference ?n1 with an outer optical cladding; a first inner cladding having an index difference ?n2 with the outer cladding; and a second buried inner cladding having an index difference ?n3 with the outer cladding of less than ?3.10?3. The second buried inner cladding moreover contains Germaniumn in a weight concentration of between 0.5% and 7%. The fiber shows reduced bending and microbending losses whilst exhibiting the optical performances of a standard single-mode fiber (SSMF).

Abstract: An optical fibre having an NA-value of less than 0.34, which optical fibre is built up of a core and an enveloping protective coating, wherein the protective coating forms the outer layer of the optical fibre, which optical fibre has an NA-value ranging from 0.15 to 0.30, with the overall external diameter of the optical fibre corresponding to the internal diameter of an element into which the end of the optical fibre is inserted.

Abstract: The present invention relates to a single mode optical fibre comprising a first central region having a radius r1, a maximum refractive index value n1 and at least one second ring surrounding said first central region, which second ring has a radius r2 and a minimum refractive index value n2, wherein n2<n1. The present invention furthermore relates to an optical communication system for multi-channel signal transmission.

Abstract: The present invention relates to a method and a device for manufacturing optical performs, in which one or more layers of glass, doped or undopod, are deposited onto the internal surface of a hollow substrate tube, which deposition is effected by supplying one or more reactive gas mixtures of glass-forming compounds tot the interior of the hollow substrate tube and subsequently generating a non-isothermal plasma in the hollow substrate tube, after which the preform is subjected to a contraction process for the purpose of forming a massive rod, from which optical fibres are drawn.

Abstract: The present invention relates to a method and a device for determining the cut-off wavelength of an optical fiber. A first aspect of the present invention is to provide a method for determining the cut-off wavelength of an optical fiber, which method provides a stable measurement, which measurement is substantially independent of the exact fiber position.

Abstract: The invention relates to a method for the use of a local area fibre optic network for enabling data communication. The method comprises the steps of supplying an intensity-modulated light signal to at least one fibre of the fibre optic network by means of a transmission unit and receiving the intensity-modulated light signal by means of the receiver unit that is connected to the fibre. The intensity of the intensity-modulated light signal is modulated for the purpose of providing a bit rate of at least 30 Gbps for the data communication. The light for providing the intensity-modulated light signal has a wavelength that ranges between 1200 nm and 1400 nm. The invention further relates to a method for altering a 10 Gigabit ethernet local area fibre optic network for the purpose of adapting the fibre optic network for data communication at a bit rate in excess of 30 Gbps. The invention also relates to a fibre optic network.

Abstract: A transmission fibre with optical amplification, comprising a core and a cladding. The core material is doped with a first dopant of a material having a higher index of refraction than the material of the cladding and with a second dopant of a material that converts pump energy in the form of light having a first wavelength into light having a second wavelength. The concentration of the second dopant within the core increases in radial direction in proportion to the distance to the centre of the core. The core material is preferably doped with a third dopant for compensating the variation in the refractive index caused by the second dopant. The cladding may comprise a cladding layer surrounding the core provided with a fourth and a fifth dopant for signal amplification and refractive index compensation, respectively, in the cladding layer. The dopants have been selected to enable amplification, using the Raman effect or stimulated emission.

Abstract: The present invention relates to a single mode optical fibre comprising a first central region having a radius r1, a maximum refractive index value n1 and at least one second ring surrounding said first central region, which second ring has a radius r2 and a minimum refractive index value n2, wherein n2<n1. The present invention furthermore relates to an optical communication system for multi-channel signal transmission.

Abstract: The present invention relates to a single mode optical fibre comprising a first central region having a radius r1, a maximum refractive index value n1 and at least one second ring surrounding said first central region, which second ring has a radius r2 and a minimum refractive index value n2, wherein n2<n1. The present invention furthermore relates to an optical communication system for multi-channel signal transmission.

Abstract: An optical fibre having an NA-value of less than 0.34, which optical fibre is built up of a core and an enveloping protective coating, wherein the protective coating forms the outer layer of the optical fibre, which optical fibre has an NA-value ranging from 0.15 to 0.30, with the overall external diameter of the optical fibre corresponding to the internal diameter of an element into which the end of the optical fibre is inserted.