Abstract:
A method for molding a chalcogenide glass lens includes providing a mold. A preformed lens of chalcogenide glass is placed within the mold. The lens has a top surface and a bottom surface. An amount of chalcogenide glass is deposited within the mold and on the top surface of the preformed lens. The mold is heated, such that the chalcogenide glass on the top surface of the preformed lens softens, melts, and bonds to the top surface of the preformed lens. A lens surface is formed in the melted chalcogenide glass to form a molded lens which is bonded to the top surface of the preformed lens. The molded lens and preformed lens assembly is then removed from the mold.
Abstract:
This invention pertains to apparatus and process for making core/clad glass fibers. The apparatus includes a central tube or receptacle connected at the top to a pressure controller and terminating in a reduced section; a side tube or receptacle positioned at about the level of the upper portion of the central tube; an outer tube or receptacle disposed around the bottom portion of the central tube terminating in a smaller section which is concentric with and spaced directly below the section of the central tube; a side arm connecting the side tube and the outer tube; and furnaces around the side, outer, and the reduced sections of the central arid the outer tubes. The process includes the steps of disposing a solid core glass rod at a point removed from hot temperature that can cause crystallization in the core glass rod, disposing a solid clad glass rod at a point removed from the core glass rod, softening to the flowing condition the solid clad glass rod, transferring the softened clad glass to a lower point, the softened clad glass having a central void therethrough, heating the softened clad glass above its crystallization temperature, cooling the softened clad glass to a draw temperature, transferring the solid core glass rod into the central void in the softened clad glass, softening to the flowing condition the solid core glass rod with the heat from the softened and cooled clad glass, and drawing the core/clad glass fiber by allowing the clad and core glasses to flow in the form of a fiber.
Abstract:
High index-contrast fiber waveguides, materials for forming high index-contrast fiber waveguides, and applications of high index-contrast fiber waveguides are disclosed.
Abstract:
An infrared lens is made from a moldable IR transmissive material and has an optically significant surface with a surface relief holographic grating. The moldable IR transmissive material is an arsenic selenide glass. The lens and the optically significant surface are manufactured as a unitary structure in a molding operation.
Abstract:
Core/clad glass optical fiber preforms free of bubbles and soot at the coclad interface are fabricated by inserting a glass core rod into a cladding glass tube sized so that space remains between them, sealing the top and bottom of the tube onto the core rod to form a sealed space between them which is relatively soot free and under a vacuum and then hot isostatically pressing the sealed composite to collapse the tube onto the rod and also collapse bubbles in the glass. Soot formation is avoided or minimized by purging the space with inert gas while the bottom of the tube is collapsed onto the rod and by sealing the top under a dynamic vacuum and at the lowest possible temperature to avoid soot formation without cracking the glass. The space is vacuum outgassed before the second seal is made. Chalcogenide fiber drawn from a preform made in this fashion exhibits very low transmission losses.
Abstract:
Disclosed is a method and apparatus for drawing an elongated glass article such as a fiber optic device. The article is drawn upwardly from a source through the surface of a quantity of molten metal having a vertical temperature gradient. The source can be an elongated solid glass preform that is vertically positioned within the molten metal such that the temperature of that portion of the molten metal adjacent the upper end region is sufficiently high to heat that region to drawing temperature. The upper end region is pulled to form a tapered root, continued pulling resulting in the formation of an elongated article from the small diameter root end. The relative position of the root is maintained with respect to the surface of the molten metal during the drawing operation. Alternatively, the glass can be drawn from an orifice located within the molten metal.The apparatus includes container means for supporting the molten metal, and external or internal means for heating and/or cooling portions of the molten metal. The container can also be provided with baffle means for dividing the container into a plurality of chambers.
Abstract:
Apparatus and method for forming ultrapure glass rods (13) or fibers (28) from a polycrystalline rod (11) in which the method comprises the steps of heating a selected short section of the rod in the first furnace (21) to form a molten zone of the rod, heating a second selected short section of the rod in a second furnace (19) which initially is separated from the first furnace by a very short gap to form a second molten zone of the rod which initially is contiguous with and part of the first molten zone of the rod to form a single molten zone 14, and then gradually moving the first and second furnaces apart to first form a rod (13) and then, ultimately, a fiber (28), of ultrapure glass in the increasingly widening gap forming therebetween.
Abstract:
This application relates generally to an optical fiber for the delivery of infrared light where the polarization state of the light entering the fiber is preserved upon exiting the fiber and the related methods for making thereof. The optical fiber has a wavelength between about 0.9 μm and 15 μm, comprises at least one infrared-transmitting glass, and has a polarization-maintaining (PM) transverse cross-sectional structure. The infrared-transmitting, polarization-maintaining (IR-PM) optical fiber has a birefringence greater than 10−5 and has applications in dual-use technologies including laser power delivery, sensing and imaging.