Abstract: A non-contact system for monitoring the tension in an optical waveguide fiber during drawing is provided. The system comprises: (a) means for sensing the motion of the fiber in a direction transverse to the direction in which the fiber is moving; (b) means for analyzing the sensed motion to determine at least one frequency component thereof; and (c) means for monitoring the frequency component so determined so as to monitor the tension in the fiber.

Abstract: Methods are provided for reducing the water content of optical waveguide fibers produced from blanks having a centerline aperture and having compositions which prevent cooling of the blank to room temperature between consolidation and drawing. In accordance with certain aspects of the invention, the water content is reduced by storing the blanks at as low a temperature as possible, preferably below about 550.degree. C. In accordance with other aspects, the water content is reduced by filling the apertures of the blanks with an inert atmosphere during storage.

Abstract: A split recoating mold for use in recoating optical waveguide fibers with a UV-curable resin is provided wherein: (1) the mold, when closed, forms a cavity for receiving the portion of the fiber which is to be recoated, the cross-sectional size and shape of the cavity being essentially equal to the cross-sectional size and shape of the original fiber; (2) the mold includes an injection port for introducing a UV-curable resin into the cavity; and (3) the mold includes means for introducing ultraviolet light into the cavity so that resin located in regions of the cavity remote from the injection port will cure prior to resin located in regions of the cavity near the injection port.

Abstract: A microelectronic semiconductor element 12 is mounted on to a header 13, and integrally combined with one or more metallic sensing electrodes 20, 21 by encapsulation in a chemically and electrically inert material 19, to provide a miniature sensor assembly suitable for the detection and measurement of oxygen and other substances.Gold or gold alloy semiconductor-device bonding wires are suitable as the metallic sensing electrodes and permit low-cost, mass-production capability. The basic assembly can be engineered in various forms for different biomedical applications and is readily modified, by the addition of appropriate electro-active films to the device surface, into a sensor for a variety of chemical and biochemical substances, including enzyme substrates.

Abstract: The invention provides a chemical-responsive field-effect transducer operating in depletion-mode, or enhancement/depletion-mode, comprising: a semiconductor material having a pair of adjacent diffusion regions (1,2) of a certain doping polarity located at the surface and separated by a channel (3) of the same doping polarity, said channel being created by diffusion, ion-implantation, epitaxial growth, or creation of a surface inversion layer by controlled processing techniques or other means. The diffusion regions and channel region are supported by an insulating substrate (4) or semiconductor substrate of opposite polarity. Electrical insulator (6) and/or ion-barrier material (7) overlies the aforementioned channel region. An electroactive material (10) overlies said insulator and/or ion-barrier, such that the electroactive material will interact with substances to which it is exposed and control the charge-carrier density in the aforementioned channel.

Abstract: Porous glass optical fiber preforms are conventionally formed by depositing many layers of glass soot on a mandrel, removing the mandrel, and heating the porous preform to form a consolidated glass article. To prevent the formation of a devitrified layer at the aperture-forming surface during the consolidation step, the rate of soot deposition is initially reduced so that a stratum of fine soot is initially deposited on the mandrel. The stratum is initially discontinuous, but after a plurality passes of the soot-producing burner, it becomes continuous. Thereafter, the formation of the remainder of the soot preform continues in a conventional manner.

Abstract: Concentrations of dopants are changed while forming a gradient index optical waveguide so that an optimal index profile is produced even though the relationship between concentration and refractive index is not linear. This is accomplished by varying the concentrations of the dopants as a function of the radial distance from the center of said core substantially as:C.sub.i (r)=C.sub.i .degree.+[(l-.xi..sub.i)(r/a).sup..alpha. +.xi..sub.i (r/a).sup.2.alpha. ]C.sub.i.sup.1where C.sub.i (r) denotes the concentration of the i.sup.th dopant as a function of radial distance r, C.sub.i.sup..degree. denotes the concentration at r=o of the i.sup.th dopant, C.sub.i.sup.1 is the total change in concentration of dopant's between r=o and r=a, .alpha. is the selected index profile, and .xi..sub.i are variable parameters relating the concentration of the i.sup.th dopant to radial distance r.

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 substantially as: ##EQU1## where .alpha..sub.i is defined by: ##EQU2## .DELTA.=(n.sub.c.sup.2 -n.sub.o.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: Disclosed is an apparatus for storing blood gas quality control reagent comprising a first variable volume, gas impermeable container for receiving the reagent. The reagent is stored exclusively in the liquid phase therein. A valved exit passageway emanates from the container which container is situated in a second container surrounding the first, a space being present therebetween and a compressed gas situated in the space. Upon opening the valve, the compressed gas decreases the volume of the first container and reagent is expelled through the exit passageway. The present device is uneffected by changes in ambient temperature since the reagent is stored exclusively in the liquid phase. The device is reusable since a portion of the reagent may be expelled without contamination of the remaining contents.

Abstract: Disclosed is an optical waveguide fiber coating system having means for cooling the hot fiber prior to the time that the fiber enters the coating apparatus. The cooling means comprises an elongated tube through which the fiber passes. Cool dry helium is flowed from a porous member or an annular slot surrounding said fiber so that it has a flow component directed radially inwardly toward said fiber and a flow component which is directed longitudinally toward the opposite end of the tube.

Abstract: A selective chemosensitive microelectronic transducer is provided for the detection and measurement of chemical properties, by engineering a field-effect transistor such that source 6 and drain 7 regions are connected to bonding pads 2 and 4, and the semiconductor bulk connected to pad 1. The metal gate 8 is extended laterally to a remote area 9, and also to bonding pad 3 via a narrow metallization track 5 designed to support only a limited, predetermined electrical current in the manner of a fusible link. External electrical access to the device is achieved with wirebonding 14, and the device is selectively sealed with an inert, impervious encapsulation material 10 such that only gate area 9 remains exposed. Electroactive materials are deposited over the offset-gate area 9, or electrodeposited using connection through 8, 5 and 3. Subsequently, link 5 is open-circuited by pulsed electrical overload, creating a floating chemosensitive gate.

Abstract: A glass optical fiber has multiple cores and a cladding. The index of refraction of all cores is greater than the index of refraction of the cladding and the index of refraction of a first core is greater then the index of refraction of a second core. The change in the ratio of light loss from the first and second cores is detected to identify perturbations of the optical fiber before it reaches a level sufficient for a secure signal to be tapped.

Abstract: A sampling device for automatic analysis apparatus in which a probe is movable along a single circular arc between a sample take-up position and a wash and/or standard solution take-up position. A wash/standard solution is delivered to the probe tip at the latter position via a vertically arranged tube. A pump is provided to pump solution up through the top of the tube and the tip of the probe contacts the surface of the meniscus formed for aspiration of a portion of the solution.

Abstract: A gradient index optical waveguide has an optimal index profile even though the relationship between concentration and refractive index is not linear. This is accomplished by varying the concentrations of the dopants as a function of the radial distance from the center of said core substantially as:C.sub.i (r)=C.sub.i.sup.0 +[(1-.xi..sub.i)(r/a).sup..alpha. +.xi..sub.i (r/a).sup.2.alpha. ]C.sub.i.sup.1where C.sub.i (r) denotes the concentration of the i.sup.th dopant as a function of radial distance r, C.sub.i.sup.0 denotes the concentration at r=o of the i.sup.th dopant, C.sub.i.sup.1 is the total change in concentration of dopants between r=o and r=a, .alpha. is the selected index profile, and .xi..sub.i are variable parameters relating the concentration of the i.sup.th dopant to radial distance r.