Western Electric Company, Inc.

At&t Technologies, Inc.

Lucent Technologies Inc.

At&t Bell Laboratories

At+t Corp.

Fitel USA Corporation

National Product Marketing

Fred P Partus

Brian Lynch

James William Fleming

Gordon Albert Thomas

Eugene A Haney

John Burnette MacChesney

Tadeusz A Olewicz

Robert M Atkins

Jay R Simpson

Gardy Cadet

William D O'Brien, Jr

Lazhar Mazlout

Adolph H Moesle, Jr

Pundi L Narasimham

Michael A Jones

Hodge E Jenkins

Ronald G Huggins

A torch and mount assembly wherein the torch, which has a plurality of gas receiving nipples is carried in a housing through which it extends. The housing has a plurality of walls forming a substantially air tight enclosure. In at least one wall of the housing are one or more leakproof fittings which are connected to similar leakproof fittings for the nipples by means of preferably flexible gas conduits within the housing. In the system, gaseous mixtures are applied from a source or sources to the fittings in the housing wall remote from the high temperatures of the torch, while the conduits within the housing are protected from mechanical and thermal stresses. An inert gas from a suitable source is introduced under pressure into the interior of the housing to reduce leakage from the torch into the housing. The atmosphere within the housing is heated, and the constituents of the housing atmosphere are monitored to aid in detecting leakage.

Housing for an optical fiber preform torch

A method and system are described for controlling the delivery of vapor from a bubbler containing a supply of liquid through which a carrier gas is bubbled and from which bubbler vapors are delivered in a vapor stream entrained with the carrier gas. In general, the present invention involves utilizing the pressure of the vapor leaving the bubbler as the specific characteristic monitored and controlled to ensure that the concentration level of carrier gas to vapor is maintained at the desired level throughout the manufacturing process. The present invention involves introducing a concentration detector within the flow path of the bubbler vapors from the bubbler and having the output of the concentration detector input to a concentration controller. The concentration controller compares the concentration value received from the concentration detector to a desired concentration value determined for the system. In order to correct for any discrepancies between the measured and desired concentration levels, the concentration controller activates the opening and/or closing of a valve, which as the concentration detector is positioned within the flow of bubbler vapor exiting the bubbler.

Methods of and systems for vapor delivery control in optical preform

An apparatus is provided comprising means for creating substantially the same or mirror image first and a second gas flow patterns near the surface of first and second transducers. The means include an inlet conduit, an inlet port, a main conduit device, and an output port. A device is also provided for causing the first transducer to send a signal to the second transducer and for measuring the time taken for the signal to travel from first transducer to the second transducer. The inlet port is coupled to the inlet conduit, preferably centrally, and the output port is coupled to the main conduit device. The inlet conduit is comprised of a first branch and a second branch. Both branches have first and second ends, the second end of the first branch being coupled to the main conduit device at a first location, and the second end of the second branch being coupled to the main conduit device at a second location. Gas preferably flows into the inlet port, part of the gas goes into the first branch and part of the gas goes into the second branch. The main conduit device is preferably comprised of a first flange, a second flange, and a main conduit. The main conduit preferably has first and second ends.

Acoustic analysis of gas mixtures

An optical fiber formed from a glass preform substantially free of OH impurities is disclosed. The optical fiber is made to be free of OH impurities by a method having the steps of introducing a moving stream of vapor mixture including at least one compound glass-forming precursor together with an oxidizing medium into a tube, while generating a hydrogen-fee isothermal plasma on an outer surface of the tube to react the mixture and produce a glassy deposit on an inner surface of the tube. The glass preform is drawn to produce the optical fiber.

Optical fiber with low OH impurity and communication system using the

A method for making a glass preform substantially free of OH impurities is disclosed. The method comprises the steps of introducing a moving stream of a vapor mixture including at least one compound glass-forming precursor together with an oxidizing medium into a tube, while generating a hydrogen-free isothermal plasma on an outer surface of the tube to react the mixture and produce a glassy deposit on an inner surface of the tube. The method uses a plasma torch or a radio frequency furnace.

MCVD method of making a low OH fiber preform with a hydrogen-free heat

The transverse cross section of a body is modified by the steps of: a) determining the extent to which the body has material in excess of a desired shape at a plurality of points, b) exposing the body to a local heat source having a temperature sufficiently high to remove material from the surface of the body, and c) moving the surface of the body in relation to the source at a speed which decreases in regions where the body has material in excess of the desired shape so as to remove more material from such regions than from other regions. In a preferred embodiment, the body is an optical fiber preform, the local heat source is the fireball of a plasma torch, and the body is moved relative to the torch by rotating the preform at a controllable angular velocity while the torch is translated along the length of the preform.

Method and apparatus for modifying the transverse cross section of a body

To attain high strength optical glass fibers, the glass preforms, from which the fibers are drawn, must generally be free of surface imperfections such as bubbles, and air lines. It has been discovered that these imperfections can be removed quickly and cleanly by contacting the preform surface with a substantial portion of the electrically conducting plasma region (the plasma fireball) extending from a plasma torch. Significantly, the surface material is substantially removed by vaporization, due to the extremely high plasma temperature (&gt;9000.degree. C. at the plasma center) of the isothermal plasma torch. Though the temperatures in the tail of the plasma fireball are substantially less than at the plasma center, the temperatures are generally still several thousand degrees centigrade. These tail temperatures typically are sufficiently high to cause vaporization of most refractory dielectrics making the inventive method applicable to the fabrication of a wide variety of articles comprising refractory dielectric bodies. Advantageously, selective etching, according to one aspect of the inventive method, is used to remove fiber preform eccentricity and to fabricate optical fiber preforms with non-circular cross-sections for such applications as fiber sensors. Selective etching can result by controlling the plasma fireball location, the rotation of the silica preform, and/or the travel of the fireball across the preform. Significantly, the fireball location is controlled, among other ways, by injecting into the torch an additional gas that has a high ionization threshold or by inserting a probe along the axis of the torch. In either case, a substantial portion of the plasma fireball is advantageously 'pushed' outside the torch for ease of contact with the silica preform surface, or any other refractory dielectric being processed.

Method for manufacturing an article comprising a refractory dielectric

The present invention is an externally installed control switch cover assembly to be used with equipment with a ribbed edge and the control switch located adjacent to the ribbed edge. More particularly, the present invention may be used on an IBM-PC computer to cover, protect and lock into position the power switch of the computer.

Control switch cover

A vapor delivery system for the manufacture of an optical preform includes a deposition bubbler (60) and another bubbler (40) referred to as a supply bubbler which is interposed between a reservoir (24) of a liquid and the deposition bubbler. Heat energy is applied to the supply bubbler and to the deposition bubbler to vaporize liquid therein. A carrier gas is introduced into the liquid in the supply bubbler at a location below the free surface and into the deposition bubbler to cause vapor of the liquid to become entrained in the carrier gas and to flow from the supply bubbler into the deposition bubbler and from the deposition bubbler to a substrate tube from which an optical preform is made. Facilities are provided for maintaining sufficient liquid in the supply bubbler and suitable temperatures of the liquid in the supply and deposition bubblers to control the vapor flow into and out of the deposition bubbler to prevent unintended perturbations in the deposition bubbler. As a result, the concentration level of the vapor which is entrained in the carrier gas and delivered to the substrate tube is maintained at a substantially constant value.

Methods of and apparatus for vapor delivery control in optical preform

An open end (61) of a tube (62) is disposed below a free surface of a treating solution (60) which is capable of reacting with a liquid effluent to provide a disposable reaction product. A pressurized gas which is non-reactive with the effluent and with the treating solution causes the effluent to be moved through the tube and discharged into contact with the treating solution. Also, the gas is flowed through a shroud (63) disposed concentrically about the tube. The gas envelops the effluent and the shroud prevents contact of the treating material with the effluent and the gas along a predetermined distance beyond the open end of the tube. This arrangement causes the treating material to react with the effluent at a location spaced from the end of the tube thereby preventing clogging of the tube. The discharge of the gas along with the liquid effluent into the treating solution causes a substantial mixing of the two liquids to provide a substantially complete reaction.

Methods of and apparatus for effluent disposal

A sealed rotary joint and method are described wherein a purge fluid is passed over a tube rotating within an end cap and through a ball bearing component of the joint.

Apparatus for supplying fluid to a rotating tube

A lightguide fiber preform is made by depositing optically suitable layers of doped silicon dioxide on an inner wall of a rotating glass substrate tube (31) which is exposed to a moving zone of heat during a deposition mode and during a mode when the tube is collapsed. During each of a plurality of passes of a torch assembly (50) in the collapse mode following deposition, a contact device (101) is in continuous engagement with the tube and is caused to apply forces to each successive increment of its length following exposure to at least an initial portion of the zone of heat to collapse incrementally the tube. Between successive ones of the plurality of passes, the contact device is moved inwardly of the tube so that each increment of length is exposed to forces which as between the successive passes are applied at points incrementally closer to the longitudinal axis (36) of the tube.

Methods of and apparatus for collapsing a preform tube into a preform

A preform from which lightguide fiber is drawn is made by depositing optically suitable layers of doped silicon dioxide on an inner wall of a rotating glass substrate tube which is exposed to a moving zone of heat during a deposition mode and during a collapse mode. During at least a first pass following the deposition mode, a contact device is caused to engage each successive increment of length of the tube during exposure to the zone of heat. The contact device causes any sagged or offset portions of the tube to be reconfigured and causes the tube to have a central longitudinal axis which is a straight line which extends between stocks of a lathe by which ends of the tube are supported. The contact device may also be used to cause the tube to have a predetermined configuration along its length. The position of the contact device relative to the maximum temperature within the moving zone of heat for each increment of length of the glass tube allows the shape of the tube to be changed and allows that shape to be retained.

Method of and apparatus for straightening and configuring a preform tube

Apparatus for supplying fluid to a rotary tube uncontaminated with ambient air comprises an end cap having an open ended bore in which an end portion of the tube may be rotatably positioned, a first conduit extending into the end cap through which fluid may be fed into the rotary tube, and a second conduit communicating with the end cap bore through which a purge fluid may be fed into and at least partially through the bore to the exterior of the end cap.

Apparatus for supplying fluid to a rotating tube comprising end cap with

A glass tube is formed having a mean cross-sectional tube wall area less than a preselected mean cross-sectional area. Additional glass differing in composition from that of the glass tube, but having an index of refraction substantially equal to that of the glass tube, is then fused onto a surface of the tube by vapor deposition, outside vapor-phase oxidation or outside vapor-phase axial deposition until the tube wall obtains the preselected mean cross-sectional area.

Growing community of inventors

Atlanta, GA, United States of America

Fred P Partus