Abstract: A device for applying, in use, electromagnetic microwave radiation in a plasma cavity. The device includes a plasma cavity present within a housing, being substantially cylindrically symmetric about a first axis, and which plasma cavity includes a cylindrical wall provided with a circumferential slit. The plasma cavity is in communication, via the slit, with a first end of an elongated microwave guide having a longitudinally extending second axis. The device is in communication in use with a microwave generating device via the other end of the microwave guide, in which the electromagnetic microwave radiation being generated may include several modes, where the device can, in use, generate microwave radiation in the slit, which microwave radiation has only one electromagnetic field distribution at least in one direction perpendicularly to the propagation direction of the microwave radiation in the microwave guide.

Abstract: The present invention relates to a method of manufacturing an optical fiber by carrying out one or more chemical vapor deposition reactions in a substrate tube, with the optical fiber exhibiting a low sensitivity to the hydrogen-induced attenuation losses at a transmission wavelength of 1550 nm. The present invention furthermore relates to an optical fiber comprising a cladding layer and a light-conducting core, which fiber has been obtained by using the present method.

Abstract: The present invention relates to a method of manufacturing an optical fiber by carrying out one or more chemical vapor deposition reactions in a substrate tube, with the optical fiber exhibiting a low sensitivity to the hydrogen-induced attenuation losses at a transmission wavelength of 1550 nm. The present invention furthermore relates to an optical fiber comprising a cladding layer and a light-conducting core, which fiber has been obtained by using the present method.

Abstract: An optical fibre for propagating a signal in different modes, including a longitudinal length “a” of a change in the tension buildup in the optical fibre and a longitudinal distance “L” between two such changes are in accordance with the equation, a<=0.5 L, for at least part of the optical fibre.

Abstract: A method of manufacturing an optical fibre, which method comprises the steps of: i) providing an optical preform, ii) heating one end of said optical preform, iii) drawing an optical fibre from the heated end of the optical preform, iv) cooling the optical fibre thus drawn in step iii), v) winding the cooled optical fibre onto a reel, with a change in the tension buildup being introduced into the optical fibre in step iv), resulting in variations in the refractive index of the optical fibre as a function of the longitudinal position.

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 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 present invention relates to a method of manufacturing an optical fibre suitable for high transmission rates, which method comprises: i) supplying one or more glass forming precursors, and possibly a dopant, to a quartz substrate tube, ii) forming a plasma in the quartz substrate tube for the purpose of bringing about a reaction mixture so as to form glass layers, which may or may not be doped, on the interior of the substrate tube, iii) collapsing the substrate tube obtained in step ii) into a perform while heating, and iv) drawing an optical fibre from the perform while heating. The present invention furthermore relates to an optical fibre suitable for high transmission rates.

Abstract: A preform for manufacturing an optical fibre or an optical fiber, where the variation in the refractive index contrast of the preform does not exceed an absolute value of 2%, measured for a preform having a length of at least 60 cm, or the deviation of the preform in relation to the average value of the profile parameter ? does not exceed an absolute value of 0.03, measured for a preform having a length of at least 80 cm. The optical fibre has a deviation from the average value of the profile shape parameter ? of maximally about 0.03.

Abstract: The present invention relates to a method for manufacturing a bar-shaped preform. The present invention further relates to a method for manufacturing optical fibers using the manufactured bar-shaped preform.

Abstract: The present invention relates to a method of manufacturing a solid preform by moving a heat source parallel to the longitudinal axis of a substrate tube, whose inner surface is coated with one or more doped or undoped glass layers, so as to collapse the substrate tube into the solid preform in a number of passes, with an etchant being supplied to the interior of the substrate tube after a number of passes of the heat source.

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 of manufacturing an optical fibre suitable for high transmission rates, which method comprises: i) supplying one or more glass forming precursors, and possibly a dopant, to a quartz substrate tube, ii) forming a plasma in the quartz substrate tube for the purpose of bringing about a reaction mixture so as to form glass layers, which may or may not be doped, on the interior of the substrate tube, iii) collapsing the substrate tube obtained in step ii) into a perform while heating, and iv) drawing an optical fibre from the perform while heating. The present invention furthermore relates to an optical fibre suitable for high transmission rates.

Abstract: The present invention relates to a method of manufacturing an optical fiber, which method comprises the following steps: i) providing a hollow substrate tube, ii) passing doped or undoped reactive, glass-forming gases through the interior of the hollow substrate tube, iii) creating such conditions in the interior of the hollow substrate tube that deposition of glass layers onto the interior of the hollow substrate tube takes place, wherein a non-isothermal plasma is reciprocated between two reversal points along the substrate tube, wherein the velocity of movement of the plasma decreases to zero at each reversal point, iv) collapsing the substrate tube thus obtained so as to form a solid preform, and v) drawing an optical fiber from said solid preform. In addition to that, the present invention relates to a preform for manufacturing an optical fiber, as well as to an optical fiber.

Abstract: The present invention relates to a method of manufacturing an optical fibre suitable for high transmission rates, which method comprises: i) supplying one or more glass forming precursors, and possibly a dopant, to a quartz substrate tube, ii) forming a plasma in the quartz substrate tube for the purpose of bringing about a reaction mixture so as to form glass layers, which may or may not be doped, on the interior of the substrate tube, iii) collapsing the substrate tube obtained in step ii) into a perform while heating, and iv) drawing an optical fibre from the perform while heating. The present invention furthermore relates to an optical fibre suitable for high transmission rates.

Abstract: A method of manufacturing an optical fibre, which method comprises the steps of: i) providing an optical preform, ii) heating one end of said optical preform, iii) drawing an optical fibre from the heated end of the optical preform, iv) cooling the optical fibre, and v) winding the cooled optical fibre onto a reel, with a change in the tension buildup being introduced into the optical fibre in step iv), resulting in variations in the refractive index of the optical fibre as a function of the longitudinal position.

Abstract: The invention relates to a method for manufacturing an optical fibre, wherein a preform is placed in a draw tower, which draw tower comprises a furnace in which one end of a preform is heated, after which an optical fibre is drawn from the heated end, wherein the heating and/or cooling of the draw furnace takes place with a maximum temperature gradient of 15° C./minute.

Abstract: The present invention relates to an apparatus for carrying out a PCVD deposition process, wherein one or more doped or undoped layers are coated onto the interior of a glass substrate tube, which apparatus comprises an applicator having an inner and an outer wall and a microwave guide which opens into the applicator, which applicator extends around a cylindrical axis and which is provided with a passage adjacent to the inner wall, through which the microwaves can exit, over which cylindrical axis the substrate tube can be positioned, and wherein at least one choke of annular shape having a length l and a width b is centred around the cylindrical axis within the applicator.

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.