Abstract:
A process for producing a mother rod useful for the production of an optical fiber which comprises hydrolyzing a silicon alkoxide to prepare a gel of a desired shape, and drying and sintering the gel to produce a block made of a silica glass. The process has the advantages that it is well adapted for mass-production, that a glass made of a B.sub.2 O.sub.3 --SiO.sub.2 system may be produced thereby and that a glass block of arbitrary shape may be readily produced.
Abstract:
A process for producing an optical transmission fiber is provided which comprises feeding highly pure halides, hydrides or organic compounds of Si and B by way of carrier gas on the outer surface of a fused silica rod or a fused silica pipe, or inner surface of a fused silica pipe, oxidizing them and depositing the products to form a pure fused silica layer or a doped fused silica layer containing B.sub.2 O.sub.3, melting the pipe and the deposited layer followed by a spinning. The SiO.sub.2 layer can alternatively contain fluorine instead of B.sub.2 O.sub.3. A further SiO.sub.2 layer can be deposited thereon to improve the spinning processability and lower the index of refraction of the B.sub.2 O.sub.3 containing layer.
Abstract:
The invention provides a method for preparing a preform for producing by drawing an optical waveguide comprising a core region and a sheath region whose refractive index varies in the radial direction, so that the index of the former is greater than those of the second. The method consists in starting from a bar of a first composition for forming the core region and in forming, by means of a plasma torch, on its surface, a deposit of a plurality of layers whose composition varies in the radial direction, is characterized in that glass powder is fed to said torch transversely to the jet of said torch; in that said bar is drawn after each layer is deposited to bring its diameter to a value close or equal to the initial diameter; and in that the chemical composition of the glass powder is changed after each layer is deposited. The preform obtained by the present method makes it possible to produce by drawing optical waveguides for applications in the field of information transmission.
Abstract:
A system for delivering a siliceous matrix material and selected dopants to an oxidizing reaction flame or the like. Each constituent is maintained in liquified form and transferred by means of an individually controlled metering pump to a nebulizing stage then passed to a burner or the like from which the materials are converted into appropriate soots. The soots are then applied to a starting member which is subsequently subjected to heat to fuse it into a drawing blank.
Abstract:
A glass dielectric fiber waveguide with a composition profile varying radially from the center to the surface, the composition profile causing a surface layer which is in compression, said composition profile being caused by (a) at least one dopant used substantially to create a stress profile wherein the surface is in compression, and (b) at least one dopant used substantially for the purpose of creating an index of refraction profile.
Abstract:
A system for delivering a siliceous matrix material and selected dopants to an oxidizing reaction flame or the like. Each constituent is maintained in liquified form and transferred by means of an individually controlled metering pump to a nebulizing stage then passed to a burner or the like from which the materials are converted into appropriate soots. The soots are then applied to a starting member which is subsequently subjected to heat to fuse it into a drawing blank.
Abstract:
A method of making glass optical waveguides by the flame hydrolysis technique. Particles of glass soot produced by flame hydrolysis are deposited on the outside surface of a mandrel to form a porous preform. The soot particles closer to the mandrel have a refractive index greater than that of the soot disposed toward the outer surface of the preform. The mandrel is removed and the resultant hollow soot preform is supported in a draw furnace through which a helium-rich gas flows. The preform is heated to a temperature sufficient to cause said soot to consolidate and simultaneously permit an optical waveguide filament to be drawn therefrom.
Abstract:
A method of depositing a layer comprising SiO.sub.2 on a surface of a substrate at a rate which is temperature independent is disclosed. The method includes combining dichlorosilane (SiH.sub.2 Cl.sub.2) with an oxidizing gas, such as O.sub.2, CO.sub.2, N.sub.2 O, H.sub.2 O, to form SiO.sub.2.
Abstract:
Procedures are disclosed for producing both core-cladding optical fibers and self-focusing optical fibers from porous germinate and/or silicate glasses obtained after phase separation and removal of the soluble phase. A glass which is separable into at least two phases one of which is soluble, is heated to cause phase separation. The soluble phase is leached out removing undesired impurities. The pores are collapsed and this glass is used to produce cores and/or cladding layers, or self focusing fibers. According to one aspect of the invention, preforms of the porous glass have their interconnected pores stuffed with a dopant. In the production of core-cladding optical fibers, the dopant modifies the index of refraction of the core and/or cladding so that the index of refraction of the core is greater than that of the cladding. The control of this index of refraction can be accomplished by addition of non silicate network formers such as GeO.sub.2 to the original melt before phase separation. These network formers will stay in the insoluble phase. In producing self-focusing fibers, the dopant may be non-uniformly deposited in order to produce a radial gradient in the index of refraction, or sodium or potassium ions may be ion exchanged into the glass for a portion of a dopant containing lithium or thallium to produce such an index of refraction gradient.
Abstract:
A method of incorporating an additive or dopant oxide in a glass body produced by the flame hydrolysis technique. Particles of the primary glass former are produced by flame hydrolysis and deposited to form a porous body which is impregnated, in part at least, with a dopant which may be dissolved or suspended in a vehicle. The body is then thermally consolidated with the dopant dispersed therein.