Abstract: A fluorine containing silicate glass substrate is heated to a temperature sufficiently high to permit fluorine to out-diffuse from the surface thereof. A surface region is formed having a gradient fluorine concentration in a direction perpendicular to the substrate surface, the region of lowest fluorine concentration having the highest refractive index. The resultant device is capable of functioning as an optical waveguide.

Abstract: Disclosed is an optical waveguide coating system having means for cooling the hot filament prior to the time that the filament enters the coating apparatus. The cooling means comprises an elongated container through which the filament passes. A coolant jacket, which surrounds the container, lowers the temperature of the filament cooling liquid in the container.

Abstract: A method of forming graded index, nitrogen-doped optical waveguides. A cylindrically-shaped porous preform comprising at least two oxides is initially formed. One of the oxides, which more readily reacts with nitrogen, has a greater concentration near the center of the preform than at the outer portion thereof. The preform is treated with a nitrogen-containing compound to form a porous body having a greater concentration of nitrogen in the central portion thereof. The porous preform is consolidated and drawn into an optical waveguide filament.

Abstract: An elongated burner, which produces a stream of metal oxide soot, comprises three adjacent housings. A centrally disposed housing contains a linear array of orifices for issuing a gas-oxygen mixture to produce a linear flame. Disposed on opposite sides of the central housing are two housings having orifices for issuing into the flame two linear streams of metal halide vapor. Gaps between the central and outer housings permit air to be aspired for stabilizing the flame. Additional flame stabilization may be achieved by providing a shield along the entire perimeter of the halide vapor streams to prevent the random aspiration of air into the sides of the flame.

Abstract: A dry stain for reticulocyte staining comprising a mixture of new methylene blue N dye, potassium acetate, and an anti-blood-clotting agent. The stain is prepared in a concentrated aqueous solution, filtered, dispensed volumetrically into tubes, and dried. The correct quantity of dye per tube is determined spectrophotometrically, and the proper ratio of dye to potassium acetate is determined by pH measurements. For staining reticulocytes, whole blood is added to the tube and mixed with the dry stain. Smears are then prepared on slides in a conventional manner for microscopic examination.

Abstract: A coupler is disclosed for properly positioning the endface of an optical waveguide filament with respect to an optoelectronic device in a repeatable fashion. Three elongated rods of deformable material are disposed in mutually contacting relationship within a bore which terminates at the device. After a filament is inserted into the aperture between the rods so that its endface is disposed adjacent to the device, an elastomeric washer is caused to deform inwardly against the rods, thereby causing them to engage the filament. Since the ends of the rods adjacent to the device are secured in the bore, the filament may be replaced by other filaments, the endfaces of which will be precisely positioned with respect to the optoelectronic device.

Abstract: A spool is disclosed for winding an optical waveguide filament during the drawing thereof. Each end of the spool is provided with an annular resilient member which forms a part of a channel for receiving the filament. The resilient member must be displaced while the filament is in contact therewith to provide a gap through which the filament can pass. After the gap closes, the filament is gripped by the resilient member. In this manner both ends of a wound filament can be secured to the ends of a spool.

Abstract: A control system for a slide centrifuge includes a ratio checking circuit which produces a signal when the ratio between the light passing through the slide and the rate of change of this light passes through a predetermined critical value. When this ratio passes through the critical value, spinning is stopped. This effectively stops spinning when the rate of reduction of blood cell density on the slide slows, thereby producing better slides for clinical analysis.

Abstract: Disclosed is a spool for shipping low expansion optical waveguide filament. The filament supporting portion of the spool is a composite structure consisting of a cylindrically-shaped barrel of material having a thermal coefficient of expansion no greater than 125.times.10.sup.-7 /.degree.C. surrounded by a layer of resilient foam material. When a filament is wound on the spool with a predetermined tension, filament breakage and entanglement are eliminated even when the spool is subjected to temperature extremes.

Abstract: A coupler for coupling an optical signal progagating in any one of a plurality of optical waveguide filaments to all of the remaining filaments. The coupler comprises a plurality of optical waveguide filaments, the end portions of which are fused together to form a unitary structure in which the filament cores are separated by only the filament cladding material. The end of the unitary structure is planar and is perpendicular to the axes of filament cores at the ends thereof. The end of the unitary structure is coated with a light reflecting material.

Abstract: A linear peristaltic pump is disclosed. The pump includes a pivotal pump arm and a flexible tube secured thereto to inhibit longitudinal tube movement. A means for applying a force to such arm, such as a spring, is provided to cause the pump arm to pivot. A stop device is disposed in the path of travel of the pump arm so that the pump arm pivotal travel may be terminated as the pump arm comes to rest against such stop device. The flexible tube is disposed adjacent a surface of the pump arm and is pivotal therewith so that the flexible tube is pinched off between the pump arm surface and the stop device as the pump comes to rest against it. A rotatable roller assembly is provided having at least one roller mounted on a rotatable roller support, the roller intermittently contacting the flexible tube as the roller support is rotated causing a quantity of liquid to be peristaltically moved within the tube.

Abstract: A method of making low loss glass optical waveguides, wherein at least one coating of glass soot is deposited by the flame hydrolysis process on a starting member. The starting member is removed from the soot preform leaving an aperture therein. While the preform is heated to its consolidation temperature, an atmosphere including a drying agent is caused to flow into the aperture and through the porous preform, thereby removing water from the preform while the soot is consolidated to form a dense glass article. The atmosphere contains optimal amounts of oxygen and drying agent to minimize leaching of dopant oxide from the preform. Since some of the dopant oxide is leached from the preform near the aperture, the central portion of the preform is initially provided with an excess amount of dopant oxide. The resultant draw blank is drawn into an optical waveguide filament.

Abstract: A method of making glass optical waveguides by the flame hydrolysis technique. Particles of glass soot produced by flame hydrolysis are deposited on the outside surface of a mandrel to form a porous preform. The soot particles closer to the mandrel have a refractive index greater than that of the soot disposed toward the outer surface of the preform. The mandrel is removed and the resultant hollow soot preform is supported in a draw furnace through which a helium-rich gas flows. The preform is heated to a temperature sufficient to cause said soot to consolidate and simultaneously permit an optical waveguide filament to be drawn therefrom.

Abstract: A method of forming an article such as an optical waveguide filament by disposing a draw blank in a cylindrical muffle. The muffle is heated to a temperature sufficient to cause a first end of the blank to reach the drawing temperature of the material thereof. A filament is drawn from the first end of the blank while a helium-containing gas flows through the muffle in such a direction that it is exhausted from that end of the muffle from which the filament is being drawn.

Abstract: First and second tractor assemblies apply a preset tension to incremental lengths of fiber which moves continuously through the apparatus. The apparatus performs the functions of fiber pulling and non-destructive testing of all of the fiber. Each tractor assembly includes a tractor wheel and belt wheels. A belt extends around the belt wheels and engages the tractor wheel in an arc. The fiber passes between the belt and the tractor wheel in this arc. The second tractor assembly has a constant torque drive with an unloaded speed which is faster than that of the first tractor assembly. The second tractor assembly pulls the fiber thereby reducing the speed by causing the constant torque device to overload and slip.

Abstract: Disclosed is a method and apparatus for winding glass optical waveguide filaments during drawing thereof. When a spool is full, the apparatus automatically changes spools, attaches the filament being drawn to a spool moved into the winding station, and severs the filament from the full spool.

Abstract: An elongated burner for producing a stream of metal oxide soot comprises a burner face having two parallel arrays of orifices for issuing a gas-oxygen mixture to produce two intersecting linear flames. Disposed between the gas-oxygen orifices is an array of orifices for issuing metal halide vapor into the flame. Two parallel arrays of orifices, one on each side of the vapor orifices and closely spaced therewith provide high velocity jets of inner shield gas on opposite sides of the vapor streams. Disposed between the inner shield gas orifices and the gas-oxygen orifices are two elongated slots which are much greater in width than the diameters of the aforementioned orifices. These slots provide a large volume, low pressure dry, nonreactive gas which prevents the flame from "backsplashing" onto the region of the vapor orifices and further prevents the deposition of soot on the burner face.

Abstract: An optical fiber junction device for coupling a pair of optical fibers with a third optical fiber. A portion of the cladding is etched from the end portions of the pair of fibers, and those end portions are then secured together in side-by-side relationship so that their endfaces are coplanar. The third fiber is so disposed that the end portion thereof is substantially parallel to the end portions of the pair of fibers, and its endface is adjacent to the endfaces of the pair of fibers. Means is provided for causing lateral movement between the endfaces of the pair of fibers and that of the third fiber to vary the amount of light coupled between the pair of fibers and the third fiber.

Abstract: An apparatus is disclosed for drawing glass optical waveguide filaments having minimal diameter variation. A draw blank is supported within an elongated, heated, tubular muffle which heats the blank to its draw temperature. Gas is supplied to that end of the muffle opposite that from which the filament is drawn. A cylindrically shaped member at least 10 cm long is disposed adjacent to the end of the blank opposite the filament to form with the inner wall of the muffle a thin, cylindrically-shaped channel through which the gas must flow. The gas stream is thus uniformly heated at the time that it reaches the root of the filament so that diameter variations due to gas turbulence are minimized.

Abstract: A method of making low loss glass optical waveguides, wherein at least one coating of glass soot is deposited by the flame hydrolysis process on a starting member. The starting member is removed from the coating material or glass soot preform leaving an aperture therein, and a tube is secured to one end of the preform. While the preform is heated to its consolidation termperature, an atmosphere including a drying agent flows from the tube into the aperture and through the porous preform, thereby removing water from the preform while the soot is consolidated to form a dense glass article. The tube can be removed, and the resultant dense glass article can be drawn into an optical waveguide fiber.