Abstract: A low loss fiber optic coupler is fabricated by forming a coupler preform having a plurality of spaced glass cores extending longitudinally through a matrix of glass having a refractive index lower than that of the cores. The preform is heated and stretched to form a glass rod which is then severed into a plurality of units. Heat is applied to the central region of each unit while the ends of the unit are pulled apart to elongate and taper inwardly the heated central region, whereby the cores of the unit are more closely spaced and are of smaller diameter at the central region than they are at the ends of the unit. The unit is then provided with a plurality of optical fibers, one of which extends from each of the cores at the endfaces of the unit. A preferred method of providing the optical fibers involves forming the coupler preform of a matrix glass that is easily dissolved in a solvent.

Abstract: A glass optical waveguide preform is formed by depositing first and second coatings of glass soot on a mandrel. The characteristics of the first coating are such that it can ultimately form the core of an optical fiber. The core-clad diameter ratio of the preform is greater than that necessary to provide the desired core-clad diameter ratio of the resultant fiber. The mandrel is removed and the porous preform is consolidated. The preform aperture is etched, rinsed and dried. One end of the preform is heated and pinched to close the aperture. The aperture is evacuated, and the remaining end of the preform is heated, the corresponding end of the aperture being caused to close. An intermediate fiber is drawn from the resultant consolidated preform, the entire aperture being closed during drawing due to the low pressure within the aperture. The intermediate fiber is severed into sections, each of which functions as a mandrel for the deposition of a further coating of cladding soot.

Abstract: A dispersion transformer for limiting the data rate of an optical fiber transmission system. A transmission optical fiber, which connects a transmitter and a receiver, may have a bandwidth much greater than that necessary to transmit a desired predetermined maximum data rate. The transmitted signal is connected to wavelength disperser means which spatially separates the different wavelength components of the transmitted signal. Each wavelength component is then propagated with a different delay by optical fiber delay means. The wavelength component which propagates with the least delay through the transmission optical fiber is subjected to the least induced delay in the optical fiber delay means and that which propagates with the greatest delay through the transmission optical fiber is subjected to the greatest induced delay in optical fiber delay means, the remaining components being subjected to intermediate delays. The delayed wavelength components are combined to form a series of broadened optical pulses.

Abstract: A low loss fiber optic coupler is fabricated by forming a coupler preform having a plurality of spaced glass cores extending longitudinally through a matrix of glass having a refractive index lower than that of the cores. The coupler preform is formed by inserting a plurality of coated optical fiber preform rods into an aperture extending axially through an elongated boule of relatively etchable matrix glass. The cladding portion of the rods, which is relatively etch-resistant, is coated with a layer of etchable glass. The coupler preform is heated and stretched to form a glass rod which is then severed into a plurality of units. Heat is applied to the central region of each unit, and the central region is elongated and tapered inwardly. When an end of the unit is immersed in acid, the matrix glass dissolves, thereby leaving the unit cores and surrounding etch-resistant cladding glass protruding from the newly formed endface of the unit.

Abstract: An optical transmission system wherein light is transmitted from a transmitter to a receiver by at least one transmission optical fiber. The system includes a dispersion transformer which receives light from one of the components, compensates for or transforms the delay distortion of the various wavelengths transmitted through the system, and provides the next component in the system with a compensated or transformed light beam. The dispersion transformer comprises means for receiving light from one of the components and dispersing/separating the light into a plurality of spatially separated beams which are directed onto the endface of a multimode optical fiber. The position of each beam on the endface of the mutimode fiber is a function of the velocity with which the light that forms the beam propagates through the transmission optical fiber.

Abstract: A method of preparing an optical device for alignment with a light beam emitter or receiver. The optical device is formed of a first glass that is resistant to dissolving in a given solvent. Extending through the device is an optical waveguide at least the cladding of which is soluble in the given solvent. At least one end of the device is immersed in the solvent to dissolve the end portion of the fiber and form a well. An optical fiber is inserted into the well where it is aligned with the fiber extending through the device.

Abstract: Disclosed is a fluid flow sonic energy reactor particularly adapted for blood hemolysis. An ultrasonic generator is provided with a tapered resonator, the small diameter end of which forms one planar surface of the reactor cavity. The reactor includes an anvil, one end of which has a central surface region that is closely spaced from the small diameter end of the tapered resonator. An O-ring is in contact with the periphery of the small diameter end of the resonator as well as the adjacent surface of the anvil to form therebetween a sealed chamber. First and second bores extend through the anvil to the central surface region thereof to introduce fluid into the chamber and remove fluid therefrom.

Abstract: Disclosed is a mode field modifier for use with an optical fiber having a core and a cladding of outside diameter d. The modifier comprises a modifier core having a refractive index n.sub.1. Surrounding the modifier core is first cladding layer having a refractive index n.sub.2 that is less n.sub.1. On the surface of the first cladding layer is a second cladding layer having a refractive index n.sub.3 which is less than n.sub.2. The modifier is tapered intermediate its ends whereby it has a large diameter end and a small diameter end. The diameters of at least the core and first cladding layer at the large diameter end are greater than the corresponding diameters at the small end. The diameter D.sub.1 of the first cladding layer at the large diameter end is greater than d. An axially disposed hole in the large diameter end receives a fiber which is held in such alignment with the mode field modifier that it is in light coupling relationship with the modifier core.

Abstract: The various wavelength components propagating in a transmission optical fiber are delayed different times. A conventional dispersion compensation system connects the transmitted signal to wavelength dispersor means which spatially separates the different wavelength components of the transmitted signal. Each wavelength component is then propagated by an optical fiber delay line the length of which is such that the delay line fibers substantially fully compensate for the differences in propagation times of the wavelength components in the transmission fiber. The amount of light collected by the delay line array can be increased and the "dead spots" due to cladding layers between adjacent fiber cores in the array can be eliminated by optimizing fiber shape and by employing staggered, multiple arrays. Also, lens arrays and/or masks can be employed at the input end of the delay line array to reduce or eliminate the cladding effects.

Abstract: A porous glass optical waveguide preform is formed by depositing a coating of glass particulate material on the lateral surface of a core which may be a porous glass body continuously produced by the axial deposition of glass particles. The core rotates and moves longitudinally in one direction with respect to two flame hydrolysis burners which emit streams of glass particles having different compositions. In addition, the two burners reciprocatingly move with respect to a portion of the length of the core. The speed of each burner varies as it traverses along its path of reciprocating motion. The thickness of the layer produced by a burner at a given point is inversely related to the speed of the burner as it passes that point. The layers formed by the completion of a single traverse by both burners combine to form a conically-shaped layer, the composition of which varies from the base toward the apex thereof.

Abstract: A method is disclosed for extruding thin-walled ceramic bodies. The method involves mixing into a homogenized batch a granular ceramic, a binder, a soluble oxidizing agent and a matrix precursor in amounts sufficient to provide a substantially water-free extrudable mixture. The batch is extruded into an atmosphere containing SO.sub.2 which permeates the extrudate and reacts with the oxidizing agent to form SO.sub.3 in situ. The SO.sub.3 catalyzes polymerization of the furfuryl alcohol to a rigid solid which prevents deformation of the extrudate.

Abstract: A glass optical waveguide preform is formed by chemical reaction of gaseous and/or vaporized ingredients within a glass substrate tube. A reactant feed tube extends into a first end of the substrate tube. One of the reactants flows through the feed tube, and another flows through the annular channel between the feed and substrate tubes. The reactants combine just downstream of the end of the feed tube and react to form particulate material, at least a portion of which deposit in the substrate tube. The output end of the feed tube traverses the substrate tube so that the region of maximum soot deposition moves along the length of the substrate tube. A hot zone traverses the substrate tube in synchronism with the feed tube to sinter the deposited soot.

Abstract: A porous glass optical waveguide preform is formed by depositing a coating of glass particulate material on the lateral surface of a core which may be a porous glass body produced by the axial deposition of glass particulate material. The core rotates and moves longitudinally in one direction with respect to a flame hydrolysis burner. In addition, the burner oscillates longitudinally with respect to a portion of the length of the core.

Abstract: A single mode optical waveguide is fabricated in a manner such that the core thereof is subjected to a stress-induced birefringence. A hollow intermediate product is formed by depositing layers of cladding and core glass on the inner surface of a substrate tube. Opposite sides of the intermediate product are heated to cause it to collapse into a solid preform foreproduct having an oblong cross-section. A layer of flame hydrolysis-produced soot having a circular outer surface is deposited on the preform foreproduct and is consolidated to form a dense glass cladding layer thereon. The TCE of the outer cladding layer is different from that of the preform foreproduct on which it is deposited so that when the resultant preform is drawn into a fiber, a stress-induced birefringence exists in the core.

Abstract: A method of inexpensively forming low-loss optical waveguide fibers having high strength. A draw blank comprising a core region surrounded by a thin layer of cladding glass is formed by a CVD technique. The blank is drawn into a preliminary fiber which passes through a double crucible arrangement whereby a tension layer is applied to the thin coating layer of the preliminary fiber and a compression layer is formed on the surface of the tension layer. The expansion coefficient of the tension layer is much greater than that of the core glass, and the expansion coefficient of the compression layer is lower than that of the tension layer.

Abstract: An optical waveguide filament comprising a cladding layer, a core and a barrier layer disposed between the core and cladding. The barrier layer comprises silica doped with B.sub.2 O.sub.3, P.sub.2 O.sub.5 and GeO.sub.2. The core consists of an inner region and an outer region, the boundary between which is referred to as the core break-point. In the outer region of the core, the concentration of B.sub.2 O.sub.3 decreases linearly from its barrier layer level to zero at the core break-point, the P.sub.2 O.sub.5 increases at a rapid rate from the barrier layer level to a first concentration level at the core break-point and the GeO.sub.2 remains at a constant value between zero and the barrier level. In the outer region of the core, the GeO.sub.2 increases from some level up to the barrier layer level to a greater value at the filament axis in a power law fashion. The P.sub.2 O.sub.

Abstract: An optical waveguide having a cladding of high purity glass and a core of high purity glass doped with an amount of P.sub.2 O.sub.5 and GeO.sub.2 to increase the refractive index thereof to a predetermined level. The ratio of P.sub.2 O.sub.5 to GeO.sub.2 is such that the softening point temperature of the core is compatible with that of the cladding. The core glass has a cation impurity level not exceeding 10 parts per million.

Abstract: A glass optical waveguide preform is prepared by chemical reaction of vapor ingredients within a bait tube. As the reactants flow through the bait tube, a hot zone traverses the tube to cause the deposition of soot in a section of the tube downstream of the hot zone. An axially disposed heater enhances the thermophoresis effect within the tube, thereby increasing deposition rate and efficiency.

Abstract: A glass optical fiber waveguide preform is prepared by chemical reaction of vapor ingredients within a bait tube. As the reactants flow through the bait tube, a hot zone traverses the tube to cause the deposition of soot in a section of the tube just downstream of the hot zone. An axially disposed heater, which is located just downstream from the hot zone in the vicinity of the soot deposit, is mechanically coupled to the burner which generates the hot zone. The heater enhances the thermophoresis effect, thereby increasing deposition rate and efficiency. Also, a gas may be flowed over the surface of the heater to confine the reactant vapors to an annular channel adjacent the bait tube wall and to prevent soot deposition on the heater. The heater may comprise an enlarged end portion to cause soot to flow toward the bait tube wall in the deposition region.

Abstract: A method for delivering vaporous source materials to an oxidizing reaction flame or the like. Each constituent is maintained in liquified form in an enclosed container that is provided with a heater for raising the temperature of the liquid to a value sufficient to provide a predetermined vapor pressure within the reservoir. The resultant vapors are transferred by means of individually controlled metering means and appropriate conduits to the reaction device. Oxygen may be added to the vapor conveying conduit or directly to the vapor utilization device.