Abstract:
Die Erfindung betrifft ein Verfahren zum Herstellen eines Quarzglaskörpers beinhaltend die Verfahrensschritte i.) Bereitstellen eines Siliziumdioxidgranulats, ii.) Bilden einer Glasschmelze aus dem Siliziumdioxidgranulat in einem Schmelztiegel und iii.) Bilden eines Quarzglaskörpers aus zumindest einem Teil der Glasschmelze, wobei der Schmelztiegel in einem Ofen enthalten ist und aus mindestens einem Material beinhaltend Wolfram oder Molybdän oder eine Kombination davon besteht. Die Erfindung betrifft weiterhin einen Quarzglaskörper, der durch dieses Verfahren erhältlich ist. Weiterhin betrifft die Erfindung einen Lichtleiter, ein Leuchtmittel und einen Formkörper, die jeweils durch Weiterverarbeiten des Quarzglaskörpers erhältlich sind.
Abstract:
A preform element, it production and fiber production methods from preform assemblies are disclosed. The preform element has a length and a center axis along its length, a first and second end defined by its length and an outer preform element surface. The preform element comprises a plurality of longitudinal structures disposed to form longitudinal hole(s) in a background material. At least one slot extending from its outer preform element surface and intersecting at least one of the longitudinal holes, wherein the at least one slot does not fully intersect the preform element. The preform element may be a preform center element or a preform ring element and may be assembled to a form part of a preform assembly for an optical fiber.
Abstract:
An optical fiber that is relatively insensitive to bend loss and alleviates the problem of catastrophic bend loss comprises a core region and a cladding region configured to support and guide the propagation of light in a fundamental transverse mode. The cladding region includes (i) an outer cladding region, (ii) an annular pedestal (or ring) region, (iii) an annular inner trench region, and (iv) an annular outer trench region. The pedestal region and the outer cladding region each have a refractive index relatively close to that of the outer cladding region. In order to suppress HOMs the pedestal region is configured to resonantly couple at least one (unwanted) transverse mode of the core region (other than the fundamental mode) to at least one transverse mode of the pedestal region.
Abstract:
The method for fabricating an optical fibre comprises the steps of inserting a primary optical fibre preform (11) having a first primary axis (x1) and an outer surface (111) into an overcladding tube (12) having a secondary primary axis (x2) and an inner surface (120), so that said outer surface and inner surface define an interior space (15); holding the primary preform (11) in a centrally inserted position within the overcladding tube (12) with said first and second primary axes (x1, x2) in substantial alignment with each other; supplying overcladding grain (13) into the interior space (15) that is limited at the lower end of the overcladding tube (12) by means of a closure (125); generating a condition of reduced pressure within the interior space (15) that is limited at the upper end of the overcladding tube (12) by means of an adjoiner (3), which holds the primary optical fibre preform (11) and the overcladding tube (12) in position; and heating the unprocessed secondary preform (1), that consists of the primary preform (11), the overcladding tube (12) and the overcladding grain (13), at its lower end to a softened state and simultaneously or subsequently drawing an optical fibre therefrom.
Abstract:
The method for fabricating an optical fiber comprises the steps of inserting a primary optical fiber preform (11) having a first primary axis (x1) and an outer surface (111) into an overcladding tube (12) having a second primary axis (x2) and an inner surface (120), so that said outer surface and inner surface define an interior space (15) ; holding the primary preform (11) in a centrally inserted position within the overcladding tube (12) with said first and second primary axes (x1, x2) in substantial alignment with each other; supplying overcladding grain (13) into the interior space (15) that is limited at the lower end of the overcladding tube (12) by means of a closure (125); generating a condition of reduced pressure within the interior space (15) that is limited at the upper end of the overcladding tube (12) by means of an adjoiner (3), which holds the primary optical fiber preform (11) and the overcladding tube (12) in position; and heating the unprocessed secondary preform (1), that consists of the primary preform (11), the overcladding tube (12) and the overcladding grain (13), at its lower end to a softened state and simultaneously or subsequently drawing an optical fiber therefrom.
Abstract:
A method for manufacturing an alkali metal optical oxide doped glass optical fiber preform and fiber. According to the method, a first glass rod is formed, preferably by an OVD method, with a refractive index delta preferably between 0.2% and 3%. A glass sleeve tube is formed, preferably by an MCVD or PVCD method. The first glass rod is inserted into the sleeve tube and the rod-tube assembly is heated and an alkali metal vapor is flowed between the sleeve tube and the first glass rod. Additional glass may optionally be formed on the inside surface of the sleeve tube prior to inserting the first glass rod and flowing the alkali metal vapor. The additional glass may be up-doped, down-doped ,or both. The sleeve may then be collapsed onto the first glass rod to form a second glass rod doped with an alkali metal oxide. The second glass rod is drawn to form a third glass rod. Additional glass may then be formed on the third glass rod to form an optical fiber preform from which optical fiber may be drawn. Alternatively, the first glass rod is removed from the sleeve tube after flowing the alkali metal vapor and before the collapse step, after which additional glass may be formed on the first glass rod to form an optical fiber preform.
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:
A method for producing a preform of an optical fiber having a complex structure with high precision, a method for producing an optical fiber, and an optical fiber are disclosed. The method for producing a preform of an optical fiber comprising a center core portion disposed in the center of the optical fiber and having an index of refraction the maximum value of which is Nc, a depressed portion disposed outside the center core portion and at least having an index of refraction the minimum value of which is Nd, a ring portion having an index of refraction the minimum value of which is Nr, and an outer cladding layer having an index of refraction the maximum value of which is No, the relationship between the indexes of refraction being Nc >= Nr > No > Nd. The method comprises a glass rod producing step of inserting a rod including at least the center core portion into a pipe including at least the depressed portion and integrating them into one piece by collapsing to produce a glass rod, a glass pipe producing step of producing a glass pipe having a ring portion, and an integrating step of inserting the glass rod into the glass pipe and then integrating them into one piece by collapsing to produce a glass body.