Abstract: A method and apparatus for making an optical fiber preform, including injecting a plasma gas source into the first end of a tubular member; generating a ring plasma flame with the plasma gas source flowing through a plasma gas feeder nozzle, the plasma gas feeder nozzle including: an inner tube, an outer tube, wherein the plasma gas source is injected between the inner tube and the outer tube to produce the ring plasma flame, such that at least a portion of the ring plasma flame is directed radially toward the inner surface of the tubular member; traversing the tubular member along the longitudinal axis relative to the plasma flame; depositing at least one soot layer on the interior surface of the tubular member by introducing reagent chemicals into the plasma flame; and fusing all of the soot layers into a glass material on the interior surface of the tubular member.

Abstract: The improved plasma torch for making synthetic silica includes use of nitrogen screen gas from outer quartz tubing to provide active environment isolation. In addition, the present induction plasma torch includes a ring disk for more compact but complete environmental protection (360 degree coverage). It also includes offsetting and switching the position of the chemical injection nozzles for allowing improved deposition in both directions, when operated in a horizontal mode. Further, the present induction plasma torch maintains laminar flow for the injected chemicals and the middle quartz tube is provided with a concave section for increasing the average enthalpy of plasma jet, thus improving the efficiency of the plasma torch. In addition, it may utilize more plasma gas inlets. It also includes chemical injection nozzles having a downward angular inclination.

Abstract: A plasma deposition apparatus for making polycrystalline silicon including a chamber for depositing said polycrystalline silicon, the chamber having an exhaust system for recovering un-deposited gases; a support located within the deposition chamber for holding a target substrate having a deposition surface, the deposition surface defining a deposition zone; at least one induction coupled plasma torch located within the deposition chamber and spaced apart from the support, the at least one induction coupled plasma torch producing a plasma flame that is substantially perpendicular to the deposition surface, the plasma flame defining a reaction zone for reacting at least one precursor gas source to produce the polycrystalline silicon for depositing a layer of the polycrystalline silicon the deposition surface.

Abstract: A plasma deposition apparatus for making polycrystalline silicon including a chamber for depositing said polycrystalline silicon, the chamber having an exhaust system for recovering un-deposited gases; a support located within the deposition chamber for holding a target substrate having a deposition surface, the deposition surface defining a deposition zone; at least one induction coupled plasma torch located within the deposition chamber and spaced apart from the support, the at least one induction coupled plasma torch producing a plasma flame that is substantially perpendicular to the deposition surface, the plasma flame defining a reaction zone for reacting at least one precursor gas source to produce the polycrystalline silicon for depositing a layer of the polycrystalline silicon the deposition surface.

Abstract: A method and apparatus for making an optical fiber preform, including injecting a plasma gas source into the first end of a tubular member; generating a ring plasma flame with the plasma gas source flowing through a plasma gas feeder nozzle, the plasma gas feeder nozzle including: an inner tube, an outer tube, wherein the plasma gas source is injected between the inner tube and the outer tube to produce the ring plasma flame, such that at least a portion of the ring plasma flame is directed radially toward the inner surface of the tubular member; traversing the tubular member along the longitudinal axis relative to the plasma flame; depositing at least one soot layer on the interior surface of the tubular member by introducing reagent chemicals into the plasma flame; and fusing all of the soot layers into a glass material on the interior surface of the tubular member.