Abstract: A photosensitive glass processing method, and article made thereby, which makes it possible to facilitate the etch depth control, minimize the surface roughness of the etched surface, improve the operating efficiency in single-side etching process, and increase the yield includes a first exposure step, in which laser light is applied to the obverse side of photosensitive glass from above it through an exposure mask by using a pulsed laser that covers the sensitivity wavelength range of the photosensitive glass, thereby forming a first exposed portion, the energy intensity per pulse of laser light being set at 10 mJ/cm.sup.2, and the total exposure energy being set at 500 mJ/cm.sup.2 ; a second exposure step, in which laser light is applied to an end surface of the photosensitive glass through another exposure mask, thereby forming a second exposed portion, the energy intensity per pulse of laser light being set at 10 mJ/cm.sup.2, and the total exposure energy being set at 15,000 mJ/cm.sup.

Abstract: A glass vessel edge chamfering method and apparatus wherein heat energy can be controlled readily and chamfering of a glass vessel having a deformed profile, local chamfering and simultaneous processing of the opposite inner and outer sides of a lip of a vessel can be performed readily and besides the efficiency in consumption of energy necessary for chamfering for one glass vessel is improved so that a glass vessel can be processed efficiently in a short time. A pair of positive and negative electrodes are opposed in a predetermined spaced relationship to an edge of a glass vessel, and flame is blown from a pair of burners into gaps between the edge of the glass vessel and the electrodes while a high voltage is applied between the electrodes. Thereupon, electric current flows between the electrodes and the glass vessel by way of the flame and heats the glass vessel by Joule heat when the electric current flows through the glass vessel.

Abstract: An apparatus for forming a porous preform that is useable to an optical fiber by extruding a plastifiable material having silica powder as a main component thereof. The apparatus includes an extruding main body having a cylinder and a screw for extruding the plastifiable material from the cylinder and a material passage member connected to the cylinder so as to communicate therewith. The material passage member has a projection member which projects into the material passage member for preventing a lamination of the plastifiable material. The apparatus also includes a molding head connected to the material passage member so as to communicate therewith.

Abstract: According to the invention, a hollow silica bar (2) is produced with a thick wall and high geometrical precision, the bar is then cleaned and an oven (24) is used able to heat the silica to its melting temperature and with respect to which the bar is moved so as to embody an external thermic glazing of the bar, an internal vapor phase depositing a vitreous coating in this bar by making circulate inside it a mixture of suitable gaseous constituents, this coating being intended for the subsequent formation of the core of the optical fibers, and an area contraction of the bar, the various temperatures of the bar required to embody these operations being obtained by varying the temperature of the oven or speed of the bar with respect to the oven.

Abstract: Short and long wavelength absorption losses contribute to loss at the operating wavelength of an optical fiber drawn from a preform. Excess losses over and above Rayleigh scattering losses have been attributed to conditions such as temperature and the speed during drawing. Typically, after optical fiber (21) is drawn from an optical preform in a furnace (23) wherein temperatures may be 2200.degree. C. or higher, the fiber is moved out of the furnace and immediately through ambient environment to other portions of a draw line such as, for example, measuring and coating apparatus. It has been found that these absorption losses may be reduced substantially by application of a magnetic field to the optical fiber after it has been drawn and prior to it being coated.

Abstract: The invention is a hollow fiber with, over the full length of the fiber and between each fiber channel (3, 4) and the core, at least one stress zone (5, 6) to create an anisotropic stress distribution which subjects the fiber core to a tensile stress. The cable design is advantageous in that it is possible to control the sign of the fiber intrinsic birefringence. The cable is thus advantageous for use as a pressure sensor or pressure transducer.

Abstract: The present invention provides a fiber coupler manufacturing apparatus comprising a pair of fiber holding portions and a fiber clamp disposed on each of the fiber holding portions for holding at least two optical fibers. A weight and pulley system is arranged wherein a first weight is coupled to each of the fiber holding portions to pull the fiber holding portions away from each other to apply tension to the optical fibers. A heating unit is disposed between the fiber holding portions and proximate to the optical fibers to heat the optical fibers. A second weight is coupled to either the fiber holding portions or the first weight and rests on a movable platform. As the movable platform descends in a vertical direction, the second weight applies additional force to the fiber holding portions and thus applies additional tension to the optical fibers.

Abstract: A curing apparatus which is supported from a base plate (68) includes a housing which includes guide members for holding a magnetron and one portion of an elliptical chamber in which is disposed a longitudinally extending bulb. Outside the housing are triangular shaped gusset plates which are adapted to mate with a pivotally moveable portion (95) in which is disposed a mating portion of the elliptical chamber and a center tube through which the drawn optical fiber extends. An exhaust system is supported from the gusset plates. Advantageously, the pivotally moveable portion may be opened pivotally to expose the center tube and facilitate removal of the center tube and its replacement. Also advantageously, the entire curing apparatus may be aligned with the fiber by moving the base plate until the drawn fiber is centered within the center tube. In yet another advantage, the present invention incorporates a plurality of slidable plates to provide easy access to the magnetrons.

Abstract: For the production of a composite glass powder of any particle size from a fine particle size, multi-component mixture of a low-melting glass powder, fillers, and additives, the fine particle size, multicomponent mixture is sintered for 10-60 minutes at a temperature at which the base glass has a viscosity of 10.sup.5 to 10.sup.6.5 dPas, and the resultant sintered cake is ground to a powder of the desired particle size. If the multicomponent mixture comprises components decomposable with the release of gas, e.g., copper carbonate, the latter are decomposed prior to sintering at a temperature below the sintering temperature. The resultant composite glass powder containing copper oxide can be used for coating varistors.

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 as 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: A method for preparing a silica glass article of improved purity is provided. The article is prepared by a sol-gel method and is then heat treated to a selected temperature between about 1500.degree. and 2200.degree. C. and maintained at the selected temperature for a predetermined period of time sufficient to remove silica crystals, inclusions, microcracks and bubbles. The resulting silica glass articles have improved purity and can be used as photomask substrates or as preforms for optical fibers.

Abstract: In a method of producing an optical fiber coupler, in which glass portions of a plurality of optical fibers are heated so as to be fusion bonded to each other and then, are heated so as to be stretched, the improvement comprising: a gas burner which acts as a heat source and has a plurality of gas nozzles arranged in an axial direction of the optical fibers so as to be fixed in position during heating of the glass portions.

Abstract: A machine is provided for molding an optical element by using a molding block having upper and lower molding dies, a sleeve die and a glass blank combined integrally with each other. The machine includes a chamber which accommodates a heating zone having a plurality of sections for heating the molding block from above and below, a deformation zone for pressing the molding dies and a cooling zone having a plurality of sections for cooling the molding block. The chamber is formed with an inlet and an outlet for the molding block. The sections of the heating zone, the deformation zone and the sections of the cooling zone are provided independently of one another. A transport member is provided for sequentially transporting the molding block through the heating zone, the deformation zone and the cooling zone, and first and second shutters are provided for opening gas supply member is provided for introducing nonoxidizing gas into the chamber.

Abstract: A method of forming an optical channel waveguide by gettering includes forming on a substrate a porous waveguide layer containing an index of refraction raising dopant in a compound; sealing a portion of the waveguide layer along a path; and reacting the component, including the index of refraction raising dopant, with a reactant in the unsealed portion of the waveguide layer to form a volatile product from the reactant and dopant to deplete the dopant in the unsealed portion of the waveguide layer and reduce its index of refraction relative to that in the path to produce a channel waveguide along the path.

Abstract: The present invention relates to a glass blank for producing optical element used for the press molding thereof, having a core glass and a surface layer covering at least the optically functional surface of the core glass. The surface layer consists of an evaporation glass. This invention also relates to the technique to mold a glass lens using the glass blank.

Abstract: A method of forming an optical waveguide which includes the steps of forming on a substrate a waveguide layer including at least one host medium and one dopant medium, one of which is more volatile than the other; and heating the waveguide layer to selectively volatize the more volatile medium along a path, raising the index of refraction and creating a waveguide along the path.

Abstract: In a device for performing measurements on at least partly transparent objects such as optical fibres a radiation beam is directed on the object. The radiation deflected by the object is imaged by means of a lens system (321, 322) on a radiation-sensitive detection system (330). As a result of refraction on interfaces between areas having a different refractive index (311, 312) in the object and between the object and the surroundings (315), dark or light bands corresponding to the projection of the interfaces are produced on the radiation-sensitive detection system (330). Thus measurements can be performed on the internal structure of the object.

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: First and second glass sheets, which are to be combined together into a single laminated glass sheet, are heated in a heating furnace so that the temperature of the first glass sheet at the exit of the heating furnace and the temperature of the second glass sheet at the exit of the heating furnace are substantially equal to each other.

Abstract: In a process for manufacturing an optical element, in which a molding material is put in molds and is heated and press-molded to manufacture an optical element, a preheating treatment of the molding material is performed before it is put in the molds at a reduced pressure and a temperature lower than a temperature during the press molding.

Abstract: A process for the production of a molded glass article is disclosed, said process comprises the steps of: applying wet treatment to a surface of a lead oxide-containing glass material, thereby forming a hydrated layer having a lower lead oxide content than that of a basic glass; heating the glass material having the hydrated layer; and press-molding the heated glass material. According to the process, a molded glass article having no cloudiness can be obtained and lead is not deposited on the surfaces of the molds used.

Abstract: Apparatus and method for continuously forming sputter-coated glass fibers. The apparatus includes a sputter vessel into which freshly drawn fiber is passed before surface contamination can occur. The sputter vessel includes modular sputtering units which are arranged to provide sputter deposition of one or more coatings onto the fiber or capillary tube as it passes through the sputter vessel. Roughing chambers may be provided on either end of the sputter vessel and include orifices sized to allow passage of the fiber through the orifice without contact. An improved sputter coating apparatus is also disclosed.

Abstract: An optical fiber resin coating device having a nipple and a die which each have gradually tapering holes through which the optical fiber is drawn. The die and the nipple have adjacent parallel flat surfaces which are spaced to created a gap through which resin is supplied by pressuring to be applied to the optical fiber. The gap between the die and the nipple and the tapered holes within the die and the nipple are all designed to produce a resin coating which is even and contains no air bubbles, especially at high optical fiber drawing rates.

Abstract: A method is presented for writing a permanent spatially periodic phase-matching second-order non-linearity grating in an optical waveguide. Single frequency exciting radiation is launched in a pair of guided modes of the waveguide in the presence of an external DC electric field applied in a direction transverse to the waveguide. The exciting radiation may be either co-propagating or counter-propagating. The above method may be refined by performing it once for an estimated value of exciting radiation frequency, testing the waveguide to determine error in the chosen estimate, erasing the grating and re-performing the method using a corrected value for the frequency of the exciting radiation.

Abstract: Anti-veiling-glare glass input window for an optical device. The window has throughout a shallow surface layer over its peripheral surfaces radiation absorbent free-metal-induced color centers. A method for preparation of such a window, such is particularly suited to be used as an input window for an image intensifier, involves pre-shaping the window from clear glass and forming color centers in a shallow surface layer over at least the peripheral surfaces of the window. If the clear glass contains reduceable metal oxides the color centers are formed by subjecting at least the peripheral surfaces of the clear glass to a reducing atmosphere at a temperature high enough to cause the reducing atmospheres reducing component to diffuse into a shallow surface layer of the window and to reduce the metal oxides to free metal atoms.

Abstract: In the production of an optical waveguide preform, particularly for the production of mono-mode optical waveguides, a tube, or several tubes, of quartz glass are fused onto a crude preform rod of quartz glass. In a known device, the crude preform rod and the quartz glass tube slid over this are clamped at the same end into jaw chucks in the headstock of the glass lathe. Since it happens that optical waveguides that have been drawn from an optical waveguide preform produced with the known device show an inadmissibly high core eccentricity, it is proposed that another jaw chuck be provided in the tailstock for the other end of the tube preform.

Abstract: The method of enhancing purity of a fused quartz body having opposed boundary surfaces, includes the steps of maintaining the body at a temperature above 1000.degree. C. and at the same time applying a polarizing potential across the boundary surfaces by electrodes in contact with the boundary surfaces so that at least some of the residual impurity ions in it are made to migrate away from one of the boundary surfaces towards the opposite one of the boundary surfaces thereof and are subsequently discharged at the opposite boundary surface. To avoid surface contamination or deformation each of the electrodes is a gaseous electrode of an at least partially ionized helium, argon, neon, krypton, xenon, nitrogen or hydrogen gas or a flame produced by combustion of hydrogen, methane, propane, butane or acetylene. The temperature during the maintaining step is advantageously from 1500.degree. C. to 2100.degree. C.

Abstract: First and second glass sheets, which are to be combined together into a single laminated glass sheet, are heated in a heating furnace so that the temperature of the first glass sheet at the exit of the heating furnace and the temperature of the second glass sheet at the exit of the heating furnace are substantially equal to each other.

Abstract: Anti-veiling-glare glass input window for an optical device. The window has throughout a shallow surface layer over its peripheral surfaces radiation absorbent free-metal-induced color centers. A method for preparation of such a window, which is particularly suited to be used as an input window for an image intensifier, involves preshaping the window from a clear glass and forming color centers in a shallow surface layer over at least the peripheral surfaces of the window. If the clear glass contains reduceable metal oxides the color centers are formed by subjecting at least the peripheral surfaces of the clear glass to a reducing atmosphere at a temperature high enough to cause the reducing atmospheres reducing component to diffuse into a shallow surface layer of the window and to reduce the metal oxides to free metal atoms.

Abstract: The invention relates to a method and apparatus for preventing the arching of glass sheets in the roller-equipped furnace of a horizontal tempering plant. In order to equalize the total thermal effect applied to the top and bottom surfaces of a glass sheet, the top surface of a glass sheet is subjected at least at the initial stage of a heating cycle to an intensified convection heat effect by blasting air into the furnace through blasting pipes (3) positioned adjacent to the top surface of a glass sheet. An object of this blasting is to compensate a vigorous heat transfer caused by hot rollers to the bottom surface of a glass sheet in the beginning of a heating cycle. In order to intensify a heat equalization between the opposite surfaces of a glass sheet, the furnace space below a glass sheet is cooled by passing the air to be blown into the furnace into a blasting manifold (3) through a heat-exchange manifold (6) positioned below a bearing surface formed by rollers (2).

Abstract: In a method of manufacturing an optical waveguide by the use of a substrate which has a first ion of a first refractive index and primary and secondary surfaces, an optical passage is formed in the substrate by diffusing through the primary surface a second ionizable species of a second refractive index greater than the first refractive index. A diffusion-accelerator layer is deposited on the secondary surface to accelerate diffusion of secondary ions resulting from the second ionizable species. To this end, the diffusion-accelerator layer is composed of an additional ionizable species which is formed into additional ions able to react with the first ions. Such reaction of the additional ions with the first ions lends itself to reduce the amount of the first ions in the substrate and to promote diffusion of the second ions into the substrate.

Abstract: Energy efficient process and apparatus are disclosed for forming glass fiber packages which are free of migration. Air from around the fiber forming bushing is passed beneath the bushing whereby it is heated by bushing heat and the heated air is then drawn into a chamber through which the glass fibers pass in heat transfer contact with the heated air. This heat transfer contact causes the water or solvent in the applied size to be evaporated and results in a migration free package.

Abstract: Fusion-splicing polarization maintaining optical fibers includes the steps of: observing a polarization maintaining optical fiber containing stress applying members in a predetermined direction, using a core direct monitoring method to obtain a reference image; aligning the pair of polarization maintaining optical fibers to be fusion-spliced; automatically rotating the fibers while observing them with the core direct monitoring method until the images of the pair coincide with the reference image; and fusion splicing the pair together.

Abstract: In a method of manufacturing a semiconductor device, at least a support body (1) and a monocrystalline semiconductor body (2) are provided with at least one flat optically smooth surface obtained by means of bulk-reducing polishing (mirror polishing), while at least the semiconductor body is provided at the optically smooth surface with an oxide layer (3). The two bodies (1 and 2) are brought into contact with each other in a dust-free atmosphere after their flat surfaces have been cleaned in order to obtain a mechanical connection. Before the bodies are brought into contact with each other, at least the oxide layer (3) on the semiconductor body (2) is subjected to a bonding-activating operation, while after a connection has been formed between the surfaces, radiation (5) of a laser is focused on the connection surface of the two bodies and material of at least the semiconductor body is molten locally near the connection surface by means of the laser radiation.

Abstract: In accordance with the invention, the functions of two TV cameras in the prior art for monitoring polymer coating concentricity and/or carbon coating thickness are accomplished by a single TV camera (48). Rather than being projected onto an opaque dispersive screen, the forward-scattered mode pattern of each of the orthogonal beams (57,58) is transmitted through a translucent screen (52,53) and reflected to an image combining device (67) which transmits both patterns to the single TV camera (48). The two beams are slightly vertically displaced to establish displaced images (72,73) of the two patterns. This allows the two patterns to be viewed simultaneously and distinguished by the TV camera. Modified electronics (FIG. 10) provide for alternate TV scanning of the two images so that a computer (22) can monitor and correct concentricity and/or carbon coating thickness in real time during fiber production.

Abstract: Glass optical elements are molded by moving molds toward one another to press the glass and controlling the movement of the molds to balance the complete formation of the molded surfaces. A first mold is moved to a position short of contact with the glass and parked. A second mold is moved into contact with the glass to drive the glass into contact with the molding surface of the first mold. This changes the shape of the optical surface in contact with the second mold so that continued movement of the first and second molds results in balanced molding with the voids between the molding surfaces and the glass being equivalent for both surfaces.

Abstract: A raw material supplying device having a gas tight tank for receiving a material to be gasified by heating; a heater for heating the raw material within the tank and a plurality of pipes for conveying a plurality of streams of gas in parallel to each other to a plurality of ports of a reaction apparatus, and a process for using the raw material supplying device. The raw material supplying device can be used in a system for manufacturing glass fibers in which the ends of the plurality of pipes are connected to the gas feed ports of at least one multi-layer burner.

Abstract: A process for producing coated, single twist glass yarns which comprises drawing a plurality of fibers formed from fibers of molten glass, applying to the fibers a sizing comprising a thermoplastic, thermosetting or photosetting composition, gathering the coated fibers into a yarn, imparting a continuous rotative twisting movement to the coated yarn and curing the coated yarn so as to polymerize and/or crosslink the sizing coating.

Abstract: A latch mechanism adapted to lock a movable pull roll support to a fixed pull roll support in a mineral fiber attenuation apparatus. A latch arm is pivotally attached intermediate its length to the movable support and is spring biased into locking engagement with a latch seat on the fixed roll support. The latching surface of the latch arm and the mating surface of the latch seat are substantially perpendicular to a plane extending through the end of the latch seat and the pivotal attachment. This causes the latch to release upon relatively low pressure being applied to the opposite end of the latch arm.

Abstract: A method for the continuous production of a tube or rod of vitreous fused silica. Silicon dioxide in particle form is heated in a crucible to the softening temperature and is withdrawn contiuously downward from a bottom outlet opening in which a shaping tool is disposed. In the annular space between the shaping tool and the bottom outlet opening the softened silicon dioxide is subjected to an electrical field. In the closed crucible, a hydrogen-containing atmosphere with a hydrogen content of at least 80% is sustained above the silicon dioxide and in the space underneath the crucible that adjoins the shaping region.

Abstract: The present invention relates to a process and a device for applying tensile forces, with no contact with solid walls, to glass sheets, in particular at high temperatures, wherein a gas or vapor is blown between the glass sheet and a wall closely approached, and parallel, to said glass sheet. Between the glass sheet and said wall a gas cushion is established, in that the sections through which the gas flows inside the air gap between the glass sheet and the wall increase on the average in the direction of streaming of the gas, so as to allow the gas speed to decrease, and a recovery in gas pressure to consequently take place. Several forms of practical embodiment of the device are disclosed.

Abstract: A method for fabricating buried waveguides on a glass substrate which contains sodium ions includes the steps of masking the substrate, performing a field-assisted ion-exchange process at low temperature to form waveguides by exchanging silver ions for the sodium ions, and performing a field-assisted ion-exchange at low temperature to bury the waveguides by exchanging potassium ions. In a preferred embodiment, the silver ions and the potassium ions are exchanged from eutectic melts.

Abstract: Continuous filament glass fiber bundles are coated with a molten thermoplastic polymer, without the addition of a size to the glass, by passing the filaments through an unpressurized pool of the polymer contained in a passage. The forces between the filaments and the unpressurized polymer interact to center the filaments in the passage as they pass through. The passage is defined by a body member and a detachable cover having contiguous surfaces joined along a longitudinal mating line which is angularly displaced from the longitudinal axis of the passage to assist in prevention of filament snagging in the melting line as they pass through the passage.

Abstract: A double crucible fiberizing apparatus and process for producing a continuous glass filament having a core fluoride-containing glass concentrically surrounded by a clad fluoride-containing glass at increased throughput speeds while simultaneously achieving increased length and uniform filament diameter are disclosed.

Abstract: A process for forming a channel waveguide in which the channel geometry and the channel index of refraction vary oppositely along the channel length to keep the modal characteristic of the channel uniform uses non-uniform heating of a channel waveguide to cause non-uniform diffusion of the channel dopant. In one embodiment, the channel is passed under a laser at a non-uniform rate to expose the channel to different numbers of laser pulses.

Abstract: A method for manufacturing glass comprises forming glass from molten mineral material, continuously discharging an auxiliary stream of molten mineral material, continuously measuring the temperature and the mass flow rate by laser means of the auxiliary stream, calculating the viscosity of the material using the measured mass flow rate and modifying a process parameter in response to the measured temperature and calculated viscosity of the auxiliary stream. The laser means is also disclosed.

Abstract: An improved purified vitreous silica body is made at high temperature by applying a polarizing potential across the boundary surfaces of the vitreous silica body or vessel to cause migration of impurities of ions away from one of the boundary surfaces thereof while the silica body is held at 1000 degrees centrigrade and during the cooling until the body is less than 800 degrees centrigrade whereby alkali ions move to one boundary of the silica body.

Abstract: Apparatus and method for forming an integral structure, such as a lens, on a fiber, such as an optical fiber, which includes a device which imparts centrifugal force to an end of the fiber while the end of the fiber is being heated. An arc or heat source which heats the end of the fiber can both rotate about the longitudinal axis of the fiber and move laterally with respect to the longitudinal axis of the fiber. The apparatus also includes a device for longitudinally moving the fiber relative to the arc. When a fiber is inserted into the apparatus, centrifugal force is exerted on the end of the fiber as the fiber is heated. The fiber is advanced longitudinally relative to the arc until a sphere of a predetermined size is formed. Then, depending upon the shape or lens desired, the sphere may be allowed to cool and be removed from the apparatus, or other operations are performed.

Abstract: A method and apparatus for the rapid on-line coating of optical fibers with two-package polymer coating systems utilizing conventional liquid fiber coaters is described. The A and B parts of the two-package coating system are continuously combined and mixed together to form a polymerizable coating liquid as the fiber is drawn. This polymerizable coating liquid is continuously delivered to the liquid coater at a rate corresponding to the rate at which it is applied to the fiber, suitable control of the delivery rate being achieved via the use of a feedback signal to the coating liquid delivery system from, e.g., the fiber coater.

Abstract: The present invention is directed to a four-step process for molding glass articles of high precision and excellent surface figure. A glass preform having an overall geometry closely approximating that of the desired final product is placed into a mold, the mold and preform are brought to a temperature at which the glass exhibits a viscosity between 10.sup.8 -10.sup.12 poises, a load is applied to shape the glass into conformity with the mold, and thereafter the glass shape is removed from the mold at a temperature above the transformation range of the glass and annealed.