Abstract:
A method of forming an alkali metal oxide-doped optical fiber by diffusing an alkali metal into a surface of a glass article is disclosed. The silica glass article may be in the form of a tube or a rod, or a collection of tubes or rods. The silica glass article containing the alkali metal, and impurities that may have been unintentionally diffused into the glass article, is etched to a depth sufficient to remove the impurities. The silica glass article may be further processed to form a complete optical fiber preform. The preform, when drawn into an optical fiber, exhibits a low attenuation.
Abstract:
Method of making a preform for microstructured optical fibres, in an aspect the method being an improved sol-gel process, wherein elongated elements, such as rods and/or tubes, extend through a tubular vessel, and being maintained in a predetermined spatial arrangement with respect to the vessel, the elongated elements being part of a final gel body resulting from the sol-gel process; a preform or part thereof for making microstructured optical fibres, the preform comprising concentric tubes and a plurality of tubes and/or rods placed between the concentric tubes; and microstructured optical fibres produced using such preforms.
Abstract:
The present invention relates to a method for manufacturing a preform for optical fibers, which method comprises the sequential steps of: i) deposition of non-vitrified silica layers on the inner surface of a hollow substrate tube; ii) deposition of vitrified silica layers inside the hollow substrate tube on the inner surface of the non-vitrified silica layers deposited in step i); iii) removal of the hollow substrate tube from the vitrified silica layers deposited in step ii) and the non-vitrified silica layers deposited in step i) to obtain a deposited tube;iv) optional collapsing said deposited tube obtained in step iii) to obtain a deposited rod comprising from the periphery to the center at least one inner optical cladding and an optical core; v) preparation of an intermediate layer by the steps of: * deposition of non-vitrified silica layers on the outside surface of the deposited tube obtained in step iii) or deposited rod obtained in step iv) with a flame hydrolysis process in an outer reaction zone using glass-forming precursors, and subsequently; * drying and consolidating said non-vitrified silica layers into a vitrified fluorine-doped silica intermediate cladding layer; and * in case preceding step iv) was omitted collapsing; to provide a solid rod comprising from the periphery to the center the intermediate layer, at least one inner optical cladding and an optical core; wherein a fluorine-comprising gas is used during the deposition and/or drying and/or consolidating and wherein the intermediate layer has a ratio between the outer diameter of the intermediate cladding layer (C) to the outer diameter of the optical core (A) that is at least 3.5; vi) deposition of natural silica on the outside surface of the intermediate cladding layer of the solid rod obtained in step v) by melting natural silica particles in an outer deposition zone to produce an outer cladding whereby a preform is obtained.
Abstract:
Ein bekanntes Rohr aus synthetischem Quarzglas für die Herstellung einer Vorform, weist eine Innenbohrung mit werkzeugfrei im Schmelzfluss erzeugter Oberflächenschicht sowie einen Innenbereich auf. Damit das Rohr keine OH-Gruppen an die Umgebung abgibt, wird erfindungsgemäss vorgeschlagen dass die Overchenschicht (30) eine Stärke von 10µm und darin einem mittleren OH-Gehalt von aximal5 Gew.-ppm sowie eine mittlere Oberflächenrauigkeit R a von maximal 0,1 µm, aufweist, und dass der an der Oberflächenschicht (30) beginnende und 10 pm vor der Außenwandung endende Innenbereich (34) einen mittleren OH Gehalt von maximal 0,2 Gew.-ppm aufweist. Ein einfaches und kostengünstiges Verfahren zur Herstellung eines derartigen Quarzglasrohres besteht darin, dass in einem Vertikalziehverfahren aus einer erweichten Quarzglasmasse kontinuierlich ein Rohrstrang gezogen wird, durch dessen Innenbohrung ein Spülgas im Durchfluss geleitet wird, das einen Wassergehalt von weniger als 100 Gew.ppb hat, und wobei das vordere Ende des Rohrstrangs (19) von einem für das Spülgas durchlässigen Strömungshindernis (26) verschlossen ist, der den Durchfluss des Spülgases (23) vermindert.
Abstract:
A method of making an optical fiber precursor includes generating vapors from an alkali metal source comprising compound containing oxygen and one or more alkali metals and applying the vapors to a surface of a glass article comprising silica at a temperature that promotes diffusion of the alkali metal into the surface of the glass article. An optical fiber has a core comprising silica and an alkali metal oxide of the form X 2 O, where X is selected from the group consisting of K, Na, Li, Cs, and Rb, wherein a concentration of the alkali metal oxide along a length of the core is uniform.
Abstract translation:制造光纤前体的方法包括从包含氧和一种或多种碱金属的化合物的碱金属源生成蒸气,并在促进碱金属扩散的温度下将蒸气施加到包含二氧化硅的玻璃制品的表面 玻璃制品的表面。 光纤具有包含二氧化硅和X 2 O 2形式的碱金属氧化物的核,其中X选自K,Na,Li,Cs和Rb,其中浓度 的碱金属氧化物沿芯的长度是均匀的。
Abstract:
In general, in one aspect, the invention features a method that includes exposing a surface to a first gas composition under conditions sufficient to deposit a layer of a first chalcogenide glass on the surface, and exposing the layer of the first chalcogenide glass to a second glass composition under conditions sufficient to deposit a layer of a second glass on the layer of the first chalcogenide glass, wherein the second glass is different from the first chalcogenide glass.
Abstract:
A method of forming an alkali metal oxide-doped optical fiber by diffusing an alkali metal into a surface of a glass article is disclosed. The silica glass article may be in the form of a tube or a rod, or a collection of tubes or rods. The silica glass article containing the alkali metal, and impurities that may have been unintentionally diffused into the glass article, is etched to a depth sufficient to remove the impurities. The silica glass article may be further processed to form a complete optical fiber preform. The preform, when drawn into an optical fiber, exhibits a low attenuation.
Abstract:
An optical waveguide (11) includes a region (22) which, after electrical poling of a guiding region (16), maintains an internal electric field induced by the poling potential. The internal electric field may arise from charge separation between regions (18, 20) induced by an adjacent poling electrode (12A), and region (22) acts to inhibit decay of the space charge and to increase the lifetime of the induced electro-optic effect. The waveguide may comprise a twin hole optical fiber (11) with internal electrodes (12A, 14A), where the region (22) comprises a borosilicate layer concentrically disposed about one of the electrodes.
Abstract:
To improve a generally known method for producing a tubular semifinished product from fluorine-doped quartz glass such that it is possible to produce a tubular semifinished product of fluorine-doped quartz glass with an inner bore of high quality while the efforts for making or treating the same are as small as possible, the present invention suggests a method comprising the following steps: (a) providing a substrate tube consisting of fluorine-doped quartz glass; (b) forming, in a deposition process, SiO 2 particles by means of plasma burners and in the presence of fluorine, and depositing said particles in layers on the cylindrical outer surface of the substrate tube rotating about its longitudinal axis with formation of a mother tube consisting of fluorine-doped quartz glass; and (c) elongating the mother tube in an elongation process to obtain the tubular semifinished product.