Abstract: Methods of making gradient property refractive elements such as gradient index lens blanks. The spatial distributions of constituents achieved by subjecting various starting assemblages to various diffusion conditions are predicted. Each such predicted spatial distribution of constituents is converted to a spatial distribution of the graded property. The property distribution which best approximates a desired distribution is selected, to thereby select one starting assemblage and one set of diffusion conditions. That assemblage and set of conditions are used in fabrication of the element.

Abstract: In accordance with the invention, a plurality of elongated refractory bodies are laminated together by placing the bodies in close adjacency, exposing the adjacent bodies to a plasma torch heat source, and moving the bodies longitudinal past the torch at a nonzero average rate which includes a reciprocating (e.g., oscillatory) component to longitudinally spread the zone of heating. Where the bodies are a rod to be laminated within a hollow tube, it is advantageous to reduce the air pressure between the rod and tube, thereby eliminating potential contaminants and, at the same time, biasing the tube to collapse against the rod. This method is particularly useful in laminating overcladding tubes to core rods to form optical fiber preforms.

Abstract: Sol-gel processing of a silica glass body is facilitated by rapid drying. The body, having been heated to a temperature of about 200.degree. C. in a hermetically sealed vessel, is vented while reducing temperature. Termination of drying coincides with reduction to atmospheric pressure.

Abstract: Heating a wet colloidal gel body in an autoclave above its 1-atmosphere boiling point, under rigorously defined conditions, avoids shrinkage during subsequent drying. As a consequence, drying rates may be increased, and handling care becomes less critical.

Abstract: Low attenuation, low dispersion of optical waveguides are provided by a process initiating with axial deposition of a high velocity core soot stream impinging on, a target at a high angle of incidence relative to the axis of rotation of the target. A core cylinder is built up axially by relative movement between the soot stream and target during deposition, the movement being non-constant in order to maintain a substantially constant diameter with a constant deposition rate. A cladding layer is then built up by deposition of soot radially on the core. Subsequent drying and sintering provides a vitreous preform which may be drawn directly into optical waveguides. Alternatively, the sintered product may be drawn down to smaller rods, which then are covered with further deposited soot cladding to a desired final thickness, and after further drying and sintering may be drawn to optical waveguides.

Abstract: A method and apparatus for simultaneously preheating cullet and removing pollutants from glass furnace gases is disclosed. Raw moist cullet having fine glass dust material and other impurities adhered to its surface is heated by furnace gases which remove the moisture and the impurities by entrainment. The dry, clean cullet is then electrically charged and used to filter the exhaust gases which have been electrostatically charged.

Abstract: In the method for forming an optical waveguide according to this invention, an optical waveguide comprising a core of quartz as a main component, and a cladding layers surrounding the core is formed by deposition of glass fine particles by flame hydrolysis deposition and vitrifying the glass fine particle layers. This method includes a step of transiently increasing a feed amount of phosphorus to a flame burner in forming glass fine particle layers to be the cladding layers. Feeding phosphorus in this step for the first time after a glass fine particle layer is deposited without feeding phosphorus to the flame burner, whereby generation of foreign objects near the core dan be suppressed.

Abstract: A low-cost, high performance 1.times.N fiber optic coupler where N>16 is presented. The coupler has a GRIN lens having an first optic fiber aligned with the optical axis of the lens at one end of the lens. The first optic fiber ends in a microlens. At the other end of the GRIN lens a bundle of tapered second optic fibers is centered on the optical axis of the lens. The microlens is formed by fusing two fibers together, stretching the fused region, jerking the fibers apart and then heating a fiber end to form the lens.

Abstract: A system for controlling the drawing of a hermetically-coated optical waveguide fiber from a preform is provided in which two measurements of fiber diameter are made and combined into an overall control signal. The first measurement is made on bare fiber in the region of the preform's root using an interference technique. The second measurement is made after the hermetic coating has been applied using a shadow technique. The first measurement provides high speed, high accuracy data needed for process control and defect detection. It is, however, subject to error due to fluctuations in the root with tractor speed. The second measurement reduces the effects of such error on the overall control signal.

Abstract: A glass sheet that has been heated nearly to a softening point thereof is preliminarily bent by a conveyor roll device while being fed along a feed path to a bending press. The conveyor roll device has a succession of first straight rolls spaced along the feed path for supporting a central region of the glass sheet, and a succession of second straight rolls spaced along the feed path for supporting a marginal edge portion of the glass sheet. The second straight rolls are vertically tilted through progressively differing angles, respectively, along the feed path with respect to the first straight rolls. The first and second straight rolls alternate with each other along the feed path.

Abstract: The present invention provides a method of manufacturing an optical component, having the steps of forming a first position aligning pattern on a surface of a substrate, forming a second position aligning recess-projection pattern conforming with the first position aligning pattern and a third position aligning recess-projection pattern having a predetermined positional relationship with the second position aligning recess-projection pattern, and applying a predetermined processing with the third position aligning recess-projection pattern used as a reference under a predetermined positional relationship with the first position aligning pattern.

Abstract: The mineral fiber forming apparatus having electrodes for heating heat softenable mineral material to form a molten mineral mass is disclosed. Organically-coated glass fiber scrap and cullet are supplied to the vessel providing the heat softenable mineral material. An impeller turbulently mixes the molten mineral mass dispersing batch into the molten mineral mass and converting water in the molten mineral bath to steam. Molten mineral material formed by the apparatus includes small seeds and gaseous occlusions. The molten mineral material is fed from an outlet port in the vessel to a rotary spinner which forms hollow mineral fibers having gaseous occlusions of between 1% and 10% by volume by centrifuging the molten mineral material through a rotary bushing.

Abstract: A coating apparatus is disclosed having a metal bath, an enclosure extending over the bath, a mandrel extending into the bath, and a gas seal mounted on the enclosure in communication with the atmosphere therein. The gas seal has a frame with a slot extending therethrough, first and second rolls aligned with the first and second ends of the slot, and a door extending between the rolls and over the seal. The door being pivotally mounted on the frame to open inwardly at the first end and outwardly at the second end.

Abstract: An improved process for producing a formed activated coke for simultaneous desulfurization and denitrification, which includes passing a ground coal through a tubular or cylindrical carbonization retort by using a hot gas stream, to subject the coal to preliminary carbonization to obtain a semi-coke, adding a caking agent to the semi-coke and forming the mixture, subjecting the formed material to carbonization to obtain a formed coke, and transferring the formed coke from the top to the bottom of a vertical multi-tubular retort of indirect heating and cooling (cooling is optional) type that includes a distribution section, a heating section, an activation section and a cooling section (the distribution section and the cooling section are optional) arranged in this order (the distribution section is at the top), to activate the formed coke.

Abstract: Method and apparatus for providing a linearly tapered bore in quartz/glass tubing includes a laser and elements for focusing the laser onto the glass tubing. The glass/quartz tubing is rotated in the laser beam and is moved vertically in the laser beam to provide a linear taper in the interior bore. The power of the laser beam is controlled and the laser beam is appropriately focused by a lens to provide a desired width of the beam at the glass/quartz tubing.

Abstract: In a process for fining oxide melts, comprising fining an oxide melt with gas generated electrochemically in situ in the oxide melt, oxygen is generated in situ electrolytically as the fining gas. Alternating, as well as direct, voltage may be employed.

Abstract: An apparatus for making dual component fibers is provided and includes a spinner having peripheral and bottom walls. The spinner includes orifices located on the peripheral wall thereof for centrifuging the dual component fibers, with the spinner being divided into a series of generally vertically-aligned compartments by baffles positioned circumferentially around the interior of the peripheral wall. A first divider is provided in the spinner for directing the first molten thermoplastic material into alternate ones of the compartments, and a second divider is provided for directing the second molten thermoplastic material into the remaining ones of the compartments so that adjacent compartments contain different thermoplastic materials. Passages are located in each of the compartments through which the respective molten thermoplastic materials flow to the orifices on the peripheral wall of the spinner.

Abstract: A method of producing an oxide glass thin film includes a process to obtain a transparent glass film, in which volatilization of additives in a porous film deposited is effectively suppressed and which can provide an oxide glass thin film having a desired arrangement of refractive index with a low optical loss. The method is for producing an oxide glass thin film, in which glass fine particles mainly containing SiO.sub.2 with additives are deposited on a substrate to form a porous thin film and then heated to form a transparent glass film. In the method, vapor of oxides of additive components is mixed in an atmosphere in which the porous thin film is heated to form the transparent glass film, whereby stopping the volatilization of the additives in the porous film deposited, preventing diffusion of the additives added to a core layer, and preventing the volatilization of glass transition temperature lowering components of additives (P.sub.2 O.sub.5, B.sub.2 O.sub.3, GeO.sub.2, etc.).

Abstract: An optical fiber bundle for heat resistance and vacuum resistance which can be used even at a very high temperature or high vacuum is provided in economical manner. This is accomplished by a process for the production of an optical fiber bundle for heat resistance and vacuum resistance, which comprises making up optical fiber filaments each having a core part and a clad part into a bundle, closely fusion-bonding the end of the optical fiber bundle with a bonding glass and then subjecting the bonding glass to a crystallization treatment to increase the heat resistance.

Abstract: Apparatus is presented for applying a coating of liquid material to a glass container and curing the coating to enhance the strength of the glass container. The apparatus includes an array of rollers in staggered alignment for coating the bottom of the container, along with differential speed belts for coating the side wall of the container and separate curing stations for curing the bottom coating and the side wall coating.