A die and method for extruding an extrudable material to form an extruded member is described. In one embodiment, the die comprises a barrier member comprising a plurality of feed channels that extend through the barrier member. Furthermore, the die incorporates a passage forming member extending from the barrier member substantially in the direction of extrusion. The feed channels are arranged with respect to the passage forming member to allow the extrudable material to substantially flow about the passage forming member to form a corresponding passage in the extruded member.

The invention relates to a process for the preparation of a quartz glass body comprising the process steps i.) Providing a silicon dioxide granulate, ii.) Making a glass melt out of silicon dioxide granulate in an oven and iii.) Making a quartz glass body out of at least part of the glass melt, wherein the oven comprises a standing sinter crucible. The invention further relates to a quartz glass body which is obtainable by this process. The invention further relates to a light guide, an illuminant and a formed body, which are each obtainable by further processing of the quartz glass body.

In one embodiment, a chalcogenide glass optical fiber is produced by forming a billet including a chalcogenide glass mass and a polymer mass in a stacked configuration, heating the billet to a temperature below the melting point of the chalcogenide glass, extruding the billet in the ambient environment to form a preform rod having a chalcogenide glass core and a polymer jacket, and drawing the preform rod.

Method and apparatus for removing bubbles from a molten substrate. The molten substrate from a furnace passes through a downtube to reach additional manufacturing tools, such as an extrusion bushing. One or more ultrasonic sensors are arranged along the downtube. The ultrasonic sensor(s) transmit ultrasonic energy into the molten substrate and measure a characteristic of the ultrasonic energy, such as a propagation time for the ultrasonic energy to be reflected back to the ultrasonic sensor(s). A bubble is detected when a change in the characteristic of the ultrasonic energy is detected. When a bubble is detected, flow through the downtube is diverted to a duct to remove a slug of molten substrate that includes the bubble.

Method for removing bubbles from a molten substrate. The molten substrate from a furnace passes through a downtube to reach additional manufacturing tools, such as an extrusion bushing. One or more ultrasonic sensors are arranged along the downtube. The ultrasonic sensor(s) transmit ultrasonic energy into the molten substrate and measure a characteristic of the ultrasonic energy, such as a propagation time for the ultrasonic energy to be reflected back to the ultrasonic sensor(s). A bubble is detected when a change in the Characteristic of the ultrasonic energy is detected. When a bubble is detected, flow through the downtube is diverted to a duct to remove a slug of molten substrate that includes the bubble.

A die and method for extruding an extrudable material to form an extruded member is described. In one embodiment, the die comprises a barrier member comprising a plurality of feed channels that extend through the barrier member. Furthermore, the die incorporates a passage forming member extending from the barrier member substantially in the direction of extrusion. The feed channels are arranged with respect to the passage forming member to allow the extrudable material to substantially flow about the passage forming member to form a corresponding passage in the extruded member.

Method and apparatus for removing bubbles from a molten substrate. The molten substrate from a furnace passes through a downtube to reach additional manufacturing tools, such as an extrusion bushing. One or more ultrasonic sensors are arranged along the downtube. The ultrasonic sensor(s) transmit ultrasonic energy into the molten substrate and measure a characteristic of the ultrasonic energy, such as a propagation time for the ultrasonic energy to be reflected back to the ultrasonic sensor(s). A bubble is detected when a change in the characteristic of the ultrasonic energy is detected. When a bubble is detected, flow through the downtube is diverted to a duct to remove a slug of molten substrate that includes the bubble.

Method for removing bubbles from a molten substrate. The molten substrate from a furnace passes through a downtube to reach additional manufacturing tools, such as an extrusion bushing. One or more ultrasonic sensors are arranged along the downtube. The ultrasonic sensor(s) transmit ultrasonic energy into the molten substrate and measure a characteristic of the ultrasonic energy, such as a propagation time for the ultrasonic energy to be reflected back to the ultrasonic sensor(s). A bubble is detected when a change in the Characteristic of the ultrasonic energy is detected. When a bubble is detected, flow through the downtube is diverted to a duct to remove a slug of molten substrate that includes the bubble.

Methods and systems for producing a hollow-core optical fiber preform and/or components thereof are described herein. In some embodiments, the method may include providing a precursor material, extruding the precursor material through a die assembly to a shaped body, and forming a hollow-core optical fiber preform or a component thereof from the shaped body. In some embodiments, providing the precursor material may include one of: heating the precursor material such that a viscosity of the precursor material reaches about 10.sup.3 to about 10.sup.7 poise, or forming a paste comprising a glass powder and a binder. In some embodiments, the hollow-core optical fiber preform may include an outer tube. In some embodiments, the hollow-core optical fiber preform may further include one of an inner tube coupled to the outer tube, or a spiral coupled to the outer tube.

A method of manufacturing a hollow core optical fiber including (a) a consolidated tube presenting step including presenting a consolidated cladding tube including a consolidated cladding first end, a consolidated cladding second end, a consolidated cladding longitudinal axis, and a consolidated cladding inner surface, the consolidated cladding inner surface defining a consolidated cladding interior and including consolidated cladding recesses (i) positioned around the consolidated cladding longitudinal axis and (ii) extending from the consolidated first end to the consolidated second end; and (b) a capillary tube coupling step comprising coupling preform capillary tubes to the consolidated cladding inner surface within the consolidated cladding recesses thus creating an optical fiber preform, each of the preform capillary tubes disposed within a different one of the consolidated cladding recesses.