Abstract: As an optical fiber (12) is being drawn, air (14) is directed at a portion of the fiber as a succession of air pulses, the pulses having a frequency near the natural frequency of the fiber portion. The frequency of the air pulses is then varied over a range of frequencies that includes the natural frequency of the fiber portion. When the air pulse frequency equals the natural frequency of the fiber portion, a resonance occurs which greatly amplifies the amplitude of the vibration of the fiber portion. The large deflection of the fiber that occurs at resonance is easy to detect, and the air pulse frequency which causes such maximum deflection is taken as being equal to the resonant frequency and therefore to the natural frequency of the fiber portion. Changes of the detected resonant frequency can be interpreted in a straightforward manner as changes in optical fiber tension which, in turn, are used to make compensatory changes of the temperature of the furnace (10).

Abstract: A method to anisotropically etch an oxide/silicide/poly sandwich structure on a silicon wafer substrate in situ, that is, using a single parallel plate plasma reactor chamber and a single inert cathode, with a variable gap between cathode and anode. This method has an oxide etch step that utilizes C.sub.2 F.sub.6, CF.sub.4, CHF.sub.3 and an inert carrier gas as the etching atmosphere. The fully etched sandwich structure has a vertical profile at or near 90.degree. from horizontal, with no bowing or notching.

Abstract: A method of molding an optical element by pressing glass material uses a cavity composed of a pair of mold members and a side mold member. Either or both of the pair of mold members are rendered slidable along the axial direction of the optical element within the side mold member used during the pressurized molding operation, so that the pair of mold members move in close contact with the contracting glass along the axial direction in the side mold member, during the cooling subsequent to the pressurized molding due to adhesion between the contracting glass and either or both of the pair of mold members. The contraction of the glass during the cooling phase is limited by the adhesive force between the glass and the mold members when at least one of the pair of mold members traverses a gap and reaches a limit of travel; thus tension will be created in the glass.

Abstract: According to the bonding method of flat electrodes of the present invention, a crystal glass material is arranged between electrodes, heated, and melted while the flat electrodes are pressured, and the melted crystal glass material is fused and re-crystallized to the surface of each flat electrode, so that the flat electrodes can be bonded with strong bonding force. Since a plate-like spacer or an application glass of a low melting point is not used in the method, disadvantages resulting from the spacer or the glass can be removed.

Abstract: This invention relates to an improved press felt conditioning treatment which controls the deposition of polymerically flocculated particulate substances in a press felt. The treatment comprises applying to the felt an effective inhibiting amount of a conditioner comprising a combination of a polymethylnaphthalene sulfonate and a type A phosphate ester comprising a nonyl phenol hydrophobe based phosphate ester having between 6 and 10 moles of ethylene oxide and a mono to diester ratio of approximately 60 to 40 or a type B phosphate ester comprising a tridecyl alcohol hydrophobe based phosphate ester having between 6 and 10 moles of ethylene oxide and a mono to diester ratio of about 60 to 40. The use of this combination was found to be especially effective at preventing the deposition of polymerically flocculated particulate substances in a press felt and paper machine.

Abstract: The method involves producing a multi-component glass doped with CdS.sub.x Se.sub.y Te.sub.z microparticles. The process has solved the conventional problems that the chalcogen element(s) to constitute the microparticles is (are) vaporized at the step for obtaining a glass melt, by specifying (a) the material to become a glass matrix and (b) the atmosphere used for obtaining a glass melt. The method involves using a mixture of elemental Cd and at least one of the elements S, Se and Te.

Abstract: A preform for a polarization retaining optical fiber is produced by making at least two bores symmetrically around a center axis of a preform comprising a core part and a cladding part which surrounds the core part, decreasing a diameter of one end of each bore, or connecting a glass tube to one end of the preform, the glass tube having a part with a smaller inner diameter near its end which is connected to the preform, inserting a first glass rod, a stressing member and a second glass rod in this order from the other end of each bore or from an end of each bore which is remote from the connected glass tube, contacting the first glass rod to the diameter-decreased end of each bore or to the part with a smaller inner diameter of the glass tube, and heating and fusing the second glass rod to the preform.

Abstract: A process for easily producing a silica glass plate having an internal refractive index distribution suitable for a planar optical waveguide involves carrying out the following steps.(a) A porous silica gel plate produced by a sol-gel method is kept in a reactor, the pressure of which is reduced to a substantially vacuum state.(b) Germanium tetrachloride gas is introduced into the reactor at a partial pressure appropriate to establish an absorption equilibrium between a desired concentration of germanium tetrachloride in said porous silica gel plate and a partial pressure of germanium tetrachloride introduced.(c) The partial pressure of germanium tetrachloride in step (b) is reduced so as to desorb germanium tetrachloride from the surface of the porous silica gel plate.(d) The porous silica gel plate having a described concentration distribution is brought into contact with water within or outside the reactor so as to fix the distribution.

Abstract: An apparatus for fushion splicing optical fiber with three pairs at clamps; the outermost pair of clamps has one rotatable clamp mechanism that is manually operated and a second rotatable clamp mechanism that is operated by a motor. A rapid fine adjustment of the alignment of the polarization maintaining optical fibers can be made.

Abstract: This invention relates to production of high purity fused silica glass doped with titania through oxidation or flame hydrolysis of a gaseous mixture and containing rutile crystals comprising a vaporizable, silicon-containing compound. Titanium-2-ethylhexyloxide, titanium cyclopentyloxide, and a titanium amide, or a combination thereof, constitute the operable titanium-containing compounds.

Abstract: A method of forming glass containers, including the steps of drying a stream of air, passing the dried air into a vacuum-insulated mixing chamber, evaporating liquid cryogen in the mixing chamber, allowing the resulting cryogen vapor to mix with the air to form a mixture at a temperature below -20.degree. C., passing the gas mixture into a vacuum-insulated manifold, and causing the gas mixture to flow from the manifold and into the insides of glass containers being formed in molds to cool the containers.

Abstract: An apparatus for fusion splicing optical fibers has one rotatable clamp mechanism that is manually operated and a second rotatable clamp mechanism that is operated by a motor. A three position stopper functions in the first position as a stopper against the optical fibers when the optical fibers are moved toward each other and in the second position as a mirror for reflecting an image of respective end faces of the optical fibers. A rapid fine adjustment of the alignment of the polarization maintaining optical fibers can be made.

Abstract: An optical fiber (24), destined to receive a hermetic coating (32), is moved through a hermetic coating apparatus (30) wherein the fiber, entering the hermetic coating apparatus at a predetermined temperature, is caused to be engaged by a reactive gas. The reactive gas, reacting with the heated fiber, is effective to cause a layer of a hermetic material to be deposited adjacent to the outer surface of the fiber. A cross-flow purge gas is effective to prevent a resultant accumulation of a soot comprising reactive components of the reactive gas adjacent to portions of the hermetic coating apparatus which become heated by the fiber. Failure to prevent the accumulation of the soot may lead to fiber abrasions and reduced fiber strength.

Abstract: An apparatus for fusion splicing optical fibers has one rotatable clamp mechanism that is manually operated, a second rotatable clamp mechanism that is operated by a motor and a twist preventing means removably coupled to the apparatus with an arm member. A rapid fine adjustment of the alignment of the polarization maintaining optical fibers can be made.

Abstract: The jet velocity along a slice opening of a papermaking machine is monitored at plural locations to provide a jet velocity profile. This jet velocity profile may be adjusted to more closely match a reference velocity profile for the jet. Preferably, microwave doppler-effect velocity sensors are utilized for sensing a jet velocity. In one specific embodiment of the invention, preamplifier and automatic gain control circuitry is used to minimize variations in the sensed signal due to changing conditions of the jet.

Abstract: A method for preparing a homogenous fluoride glass containing high purity BaF.sub.2 through the CVD process using a gaseous mixture containing a barium .beta.-diketonate complex service as a first starting material and represented by the following general formula (1) of: ##STR1## where (i) R and R' are each --C(CH.sub.3).sub.3 ; or (ii) R is CH.sub.2 CH.sub.2 CH.sub.3 and R' is --C(CH.sub.3).sub.3 ; or (iii) R and R' are each CF.sub.3 ;a gaseous or vaporizable compound of the metallic element constituting said fluoride glass, the gaseous or vaporizable compound serving as a second starting material; and a fluorine-containing gas serving as fluorinating agent. Further provided is a process for preparing a perform for a fluoride optical fiber which is low in transmission loss, by depositing the fluoride glass over the interior wall of a cylindrical tube or the wall of rod-like glass substrate through the CVD process following by collapsing.

Abstract: In the manufacture of optical fibers according to the PCVD method, a method is provided wherein the yield of the method (.eta.), in particular at increased deposition rates (m), is raised by reducing the geometrical taper, without forming optical tapers. This is obtained in that glass is deposited in layers on the inside of a glass tube and, simultaneously, on a glass rod having a circular cross-section, which rod is arranged inside the glass tube, such that its longitudinal axis coincides with that of the glass tube, the radius of the glass rod being adjusted to at most 0.67 times and at least 0.2 times the inner radius of the glass tube, and the glass rod being removed from the glass tube upon completion of the deposition process.

Abstract: An apparatus and a method for forming a three-dimensional article with thermosetting material on the basis of a three-dimensional information on the article by means of an ink jet method. The material is jetted from at least one ink jet head to a stage and laminated thereon. The laminated material is supplied with heat by a heat source so that it is cured. In this process, a jetting direction of the material from the ink jet head to the stage and/or a jetting amount of the material jetted from the ink jet head is changed in accordance with the information by a control unit, thereby forming a solid article having a desired three-dimensional shape.

Abstract: A web charging apparatus, for use in a coating system for applying various coating liquids onto a web which has been previously charged by a static field in which conductive wires form a corona discharge electrode. The diameter of the wires is in a range of 100-200 .mu.m, and the tension of the wires is not less than 1 kg. Intermediate holding frames for holding the wires are also provided. The web charging apparatus reduces the voltage irregularities in the width direction of the web and the irregular thickness of the coating liquid in the transfer direction.

Abstract: A microtest plate is characterized by a tray conveniently moulded of foam plastics, having a multiplicity of compartments and a multiplicity of individual wells fitted into the compartments, at least some of the wells preferably being moulded integrally with one another, and preferably being arranged in one or more rows.