摘要:
A quartz glass tube as a semi-finished product for an optical component that has an inner bore extending along a tube centre axis for the acceptance of a core rod and a tube wall limited by an inner casing surface and an outer casing surface is already known; within said tube wall an inner region made of a first quartz glass and an outer region made of a second quartz glass with a different index of refraction surrounding the inner region contact one another at a contact surface which runs around the centre axis. In order to provide a quartz glass on this basis that facilitates the production of optical components for special applications such as laser-activated optical components in wand or fibre form, the invention states that the contact surface has a non-round course in the radial cross-section and the inner casing surface has a circular course.
摘要:
A method of making a microstructured optical fiber preform uses the plasma fusion of a powder layer deposited onto a substrate under conditions that prevent the deposited layer from completely densifying, thereby yielding the formation of bubbles within the layer. By systematic control of powder melt and delivery, while maintaining the process temperature below a temperature associated with densifying the deposited layer, the powder particles densify only partially on the substrate and create bubbles of a fairly narrow (and thus controllable) diameter range within a defined region of the preform. Upon drawing a fiber from the preform, the bubbles will extend into gas lines, forming a desired microstructure arrangement.
摘要:
Disclosed is a plasma torch for overcladding a primary preform of an optical fiber. The plasma torch includes a confinement tube for confining an induced plasma and a torch base. The torch base has a ceramic surface internal to the confinement tube. The plasma torch has extended life even at high input powers.
摘要:
The invention embraces a method for manufacturing an optical fiber preform. The primary preform is overcladded by projecting silica grain under a plasma torch, wherein, during overcladding, at least one region adjacent to the plasma torch is cooled by gas provided by at least one cooling nozzle. The invention facilitates low-cost preform overcladding in a way that limits the incorporation of impurities into the silica overcladding.
摘要:
Glass is produced by depositing presintering composition on a preform set into move in front of a plasma torch which moves back and forth substantially parallel to a longitudinal direction of the preform, a first feed duct feeds the plasma with grains of the presintering composition while optionally a second feed duct feeds the plasma with a fluorine or chlorine compound, preferably a fluorine compound, mixed with a carrier gas.
摘要:
Method for overcladding an optical fiber preform with a given target diameter (D0) of the final preform includes providing a primary preform to be overcladded, and successively depositing first overcladding layers by projecting and vitrifying silica particles on the primary preform moving in relative translation with a plasma torch. Each first overcladding layer has a given uniform thickness (d) and is deposited at a given, constant silica particle flow rate and at a given, constant translation speed. The method also includes the detection of a preform diameter (D1) greater than a given threshold (S) and the deposition of a final overcladding layer having the remaining required thickness (D0−D1) at a constant silica particle flow rate and at a reduced translation speed. The inventive method enables a preform to be overcladded efficiently with improved yield and high quality.
摘要:
A system for fabricating an optical fiber preform including glazing the outside surface of the preform using inductive heating, the system including a plasma torch for localized heating of the preform during the glazing, and an injector for injecting into the plasma in the area of the outside face of the preform on which the plasma impinges a gas which is substantially free of silica particles to reduce the power of the plasma during the glazing operation.
摘要:
The invention relates to an inductive thermal plasma torch comprising a confinement tube that comprises, longitudinally in relation to the tube, metal fingers which are insulated from each other, an ignition device that comprises an igniter (4) and an igniter support (1, 3), the purpose of the igniter (4) being to initiate a discharge in the plasma of the torch, the support having an electrically conductive end (1) which is connected to the electrical earth (2) of the plant and another, electrically insulating, end (3) which carries the igniter, the ignition device also comprising an electrically conductive connection (5) connecting the igniter (4) to the electrically conductive end (1) of the support so that the igniter is able to initiate the discharge in the plasma, the electrically conductive connection (5) having a section that is sufficiently narrow to limit the intensity of the current capable of passing through the igniter (4) in order to avoid electrical arcing by capacitive discharge between the ignition device and another part of the torch.
摘要:
Even if an optical fiber obtained by drawing a preform is exposed to hydrogen atmosphere, an OH peak in the optical fiber at wavelength of about 1385 nm hardly rises regardless of the condition of drawing.
摘要:
The invention relates to an optical fiber preform comprising an optical core, optical cladding, and an outer sheath, in which the outer sheath includes a peripheral zone containing 20% to 100% by weight alumina and 80% to 0% by weight silica. Such a preform makes it possible to obtain optical fibers having improved mechanical strength and improved impermeability to hydrogen.