Abstract: A glass optical waveguide filament preform is prepared by chemical reaction of vapor ingredients within a glass bait tube. A reactant feed tube extends into one end of the bait tube and terminates just short of the hot zone where reaction occurs. The end of the feed tube traverses the bait tube along with the burner which generates the hot zone. Reactants flow radially from slots in the end of the wall of the feed tube and combine with a flushing gas to form a mixture which flows in a spiral path through the hot zone.

Abstract: A method of forming a preform or blank for a high bandwidth gradient index optical filament, the preform itself and the resulting optical filament is disclosed. The preform which ultimately forms the optical filament includes a barrier layer between a tubular starting member which comprises the cladding and the core, the index of refraction of the barrier layer being equal to or less than the index of refraction of the tubular starting member; there being no step increase in the index of refraction of the barrier layer at the barrier layer-cladding interface nor of the core at the core-barrier layer interface of the optical filament. The barrier layer is formed from a base glass, a first dopant B.sub.2 O.sub.3, and at least one other dopant which is maintained substantially constant in the barrier layer and then gradually varied during the formation of the core. The quantity of B.sub.2 O.sub.

Abstract: A system for delivering a siliceous matrix material and selected dopants to an oxidizing reaction flame or the like. Each constituent is maintained in liquified form and transferred by means of an individually controlled metering pump to a nebulizing stage then passed to a burner or the like from which the materials are converted into appropriate soots. The soots are then applied to a starting member which is subsequently subjected to heat to fuse it into a drawing blank.

Abstract: A method of forming a preform or blank for an optical filament, the preform itself and the resulting optical filament is disclosed. The preform is formed by providing a substantially longitudinally continuous core member and affixing it to a starting member. Particulate material is applied to the exterior surface of the core member to form an adherent coating having an index of refraction less than that of the core member. The starting member and the core member are longitudinally translated while simultaneously applying the adherent coating of particulate material to the core member to form a continuous and substantially homogeneous adherent coating of substantially uniform thickness.

Abstract: A method of forming a preform or blank for a high bandwidth gradient index optical filament, the preform itself and the resulting optical filament is disclosed. The preform which ultimately forms the optical filament includes a barrier layer between a tubular starting member which comprises the cladding and the core, the index of refraction of the barrier layer being equal to or less than the index of refraction of the tubular starting member; there being no step increase in the index of refraction of the barrier layer at the barrier layer-cladding interface nor of the core at the core-barrier layer interface of the optical filament. The tubular starting member is formed of a base glass and at least one dopant, the index of refraction of the tubular starting member being in excess of said base glass. The barrier layer is formed from a base glass and at least one dopant which is maintained substantially constant in the barrier layer.

Abstract: A hydrolyzing flame technique is used to build up glass soots of at least two different compositions upon a rotating starting member. The process is repeated until the soots define at least one helically-oriented body of soot of one composition completely enveloped by a soot of a second composition. The soot-covered starting member is then subjected to heat to fuse it whereupon the soots are fused into compositions exhibiting different indices of refraction. The member can then be drawn into a elongate structure comprising an optical waveguide extending helically through the body of the structure.

Abstract: An optical waveguide for a communication system includes a graded index core formed from at least three glass-forming compounds with a profile having at least two .alpha.-type index profile terms.The core has a refractive index which is n.sub.c at the center of the core and which varies as a function of the radial distance r from the center of the core subststantially as: ##EQU1## where .alpha..sub.i is defined by: ##EQU2## where N.gtoreq.2,.DELTA.=(n.sub.c.sup.2 -n.sub.0.sup.2)/2n.sub.c.sup.2,n.sub.o is the refractive index of said compounds at r=a,N.sub.c =n.sub.c -.lambda.dn.sub.c /d.lambda. where .lambda. is the wavelength of the light source, and the quantities .DELTA..sub.i are parameters which can be varied provided the condition ##EQU3## is satisfied.

Abstract: A multiple mode optical waveguide includes a glass core and a glass cladding around the core. In order to promote coupling between guided modes of light propagation, the core has cylindrical perturbations spaced along its length. The perturbations include index of refraction variations in rings within the core.

Abstract: Apparatus for forming a vapor of material to be hydrolyzed and/or oxidized and entraining the vapor in a carrier gas. The source material, in liquid form, is pumped to a point in the column above a porous packing. As the liquid progresses downward through the packing, it encounters a rising countercurrent of carrier gas. The source material vaporizes and is delivered to vapor deposition by the carrier gas. The source material vaporized in the apparatus may alternatively be delivered to an externally heated tubular reactor, or to any other kind of chemical vapor deposition (CVD) reactor.

Abstract: A hand-held device for causing a blood sample to be controllably drawn into a flexible envelope or the like. The envelope is placed between a rigid and a hinged member disposed within the housing of the device, and a roller advanced along the hinged member to progressively compress the envelope. When the wheel is moved back along its path, the envelope is allowed to progressively expand thereby drawing the blood sample into the envelope.

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 hydrolyzing flame technique is used to build up glass soots of at least two different compositions upon a rotating starting member. The process is repeated until the soots define at least one helically-oriented body of soot of one composition completely enveloped by a soot of a second composition. The soot-covered starting member is then subjected to heat to fuse it whereupon the soots are fused into compositions exhibiting different indices of refraction. The member can then be drawn into a elongate structure comprising an optical waveguide extending helically through the body of the structure.

Abstract: In making a preform for an optical waveguide, the bait rod is coated with carbon. After the preform is built up on the bait rod, it is easily removed. The carbon coating produces a smooth improved inner surface in the preform, thereby eliminating flaws which otherwise may be present when the preform is drawn into a waveguide.

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 pipetter for drawing fluid into capillary tubes and the like. A capillary tube is forced into an adapter coupled to one end of a vented, flexible tube. A compression wheel rides in a guideway adjacent the tube, and is rolled to continuously vary the point at which the tube is compressed in the manner of a peristaltic pump. Manual rolling of the wheel away from the capillary tube produces sufficient suction in the tube to cause liquid to be drawn into it. The pumping action is reversible in that rolling the wheel back toward the capillary tube will cause fluid to be expelled. Provision is made to prevent undesirable "compression set" as a result of long term static of the flexible tube during periods of non-use.

Abstract: A coating assembly including a recessed housing for receiving a split coating die, and a thrust block for urging the die against a die closing plate. Aligned passages extending through each of the elements are accessed through a split or slot in the side of each element so that an optical waveguide can be inserted into the apparatus from the side, rather than threaded endwise through the apparatus. Liquid coating material is introduced into the passages, the coating die serving to determine the thickness of the coating which is ultimately formed upon the waveguides.

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 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.