Abstract:
In the manufacture of preforms for optical fibres, the materials of the core (.alpha.) and of the light-conducting cladding layer (.beta..sub.1) are previously deposited from the gaseous phase. Deposition time is here considerably reduced in that only the materials of the core (.alpha.) and a part of the light-conducting cladding layer (.beta..sub.1) are deposited from the gaseous phase and the remaining light-conducting cladding material (.beta..sub.2 +.beta..sub.3) is supplied as pre-formed tubes of cladding material.
Abstract:
A method of producing a uniform silica glass block comprising using silica powder as a raw material, and treating it at high temperature and pressure by a hot press and/or a hot isostatic press in vacuum or in an inert gas atmosphere, preferably with a capsule of silica glass or a high-melting point metal. By conducting calcination in fluorine, chlorine or their compound gas and then in oxygen, the OH group content of the silica glass can be reduced dramatically.
Abstract:
A semiproduct for use in the manufacture of light conducting fibers comprising a core of synthetic quartz glass having a thickness of 6 to 400 mm, the quartz glass containing less than 10 ppm hydroxyl ions and having, in the near infrared spectral range, an optical loss totaling less than 4 dB/km, measured in the mass, the core being fused with a jacket having a wall thickness of 2 to 20 mm and consisting essentially of synthetic quartz glass containing more than 4,000 ppm of fluorine, the jacket having a length of at least 200 mm; a method of producing the same and light conducting fibers derived therefrom.
Abstract:
One aspect relates to a light guide comprising a jacket and one or more cores, wherein the jacket surrounds the cores. Each core has a refractive index profile perpendicular to the maximum extension of the core, wherein at least one refractive index nK of each refractive index profile is greater than the refractive index nM1 of the jacket. The jacket is made of silicon dioxide and has an OH content of less than 10 ppm, a chlorine content of less than 60 ppm, and an aluminium content of less than 200 ppb. One aspect also relates to a silicon dioxide granulate I, characterized by a chlorine content of less than 200 ppm and an aluminium content of less than 200 ppb, in each case based on the total weight of the silicon dioxide granulate I.
Abstract:
A method for producing a large quartz-glass pipe is provided. In a first forming step, an intermediate cylinder made of quartz glass and having an intermediate-cylinder wall thickness and outside diameter is formed by using a forming tool and is then cooled. In a second shaping step, at least one length segment of the cooled intermediate cylinder is fed to a heating zone, heated to a softening temperature zone by zone therein, and, while rotating about the longitudinal axis of the intermediate cylinder, shaped into the large quartz-glass pipe having a final wall thickness and outside diameter. The quartz glass is synthetically produced and has an average hydroxyl group content of 10 ppm by weight or less. If the intermediate cylinder is divided into length segments of 1 cm, adjacent length segments have a difference of less than 2 ppm by weight in the average hydroxyl group content thereof.
Abstract:
A manufacturing method according to an embodiment of the invention includes a step of calculating Pj0.1 satisfying (62.6×JOH+1175)×Pj=0.1, where Pj is an optical power ratio at the wavelength 1383 nm of a portion corresponding to a cladding material of an MCF after drawn, and an outer diameter ratio Pcc0.1 of core portions to core rods to obtain Pj0.1. The core rods have an outer diameter 2R0.1 satisfying the condition that a ratio Pcc is not less than the ratio Pcc0.1, and the cladding material has holes formed in a diameter larger by C (not less than 0.15 mm and not more than 1.5 mm) than the outer diameter of the core rods.
Abstract:
A porous layer is formed by depositing a silica glass particle around a core rod. The porous layer is dehydrated. The dehydrated porous layer is sintered under a decreased pressure until the dehydrated porous layer becomes a translucent glass layer containing a closed pore. The translucent glass layer is vitrified under an ambient atmosphere including an inert gas other than a helium gas.
Abstract:
The present invention provides a synthetic silica glass for an optical member in which not only a fast axis direction in an optical axis direction is controlled, and a birefringence in an off-axis direction is reduced, but a magnitude of a birefringence in the optical axis direction is controlled to an arbitrary value, such that an average value of a value BR cos2θxy defined from a birefringence BR and a fast axis direction θxy as measured from a parallel direction to the principal optical axis direction is defined as an average birefringence AveBR cos2θxy, and when a maximum value of a birefringence measured from a vertical direction to the principal optical axis direction of the optical member is defined as a maximum birefringence BRmax in an off-axis direction, the following expression (1-1) and expression (2-1) are established: −1.0≦AveBR cos2θxy
Abstract:
The present invention relates to a method for manufacturing a preform for optical fibers, wherein deposition of glass-forming compounds on the substrate takes place. The present invention furthermore relates to a method for manufacturing optical fibers, wherein one end of a solid preform is heated, after which an optical fiber is drawn from said heated end.
Abstract:
The invention relates to a method for producing a blank mold from synthetic quartz glass by using a plasma-assisted deposition method, according to which a hydrogen-free media flow containing a glass starting material and a carrier gas is fed to a multi-nozzle deposition burner. The glass starting material is introduced into a plasma zone by the deposition burner and is oxidized therein while forming SiO2 particles, and the SiO2 particles are deposited on a deposition surface while being directly vitrified. In order to increase the deposition efficiency, the invention provides that the deposition burner (1) focuses the media flow toward the plasma zone (4) by. A multi-nozzle plasma burner, which is suited for carrying out the method and which is provided with a media nozzle for feeding a media flow to the plasma zone, is characterized in that the media nozzle (7) is designed so that it is focussed toward the plasma zone (4). The focussing is effected by a tapering (6) of the media nozzle (7).