Abstract: A method of manufacturing an optical fiber and related devices using an apparatus having an elongated microwave guide coupled to a resonant cavity formed of an outer cylindrical wall and inner cylindrical wall having a slit with a width W and configured to deliver microwave energy having a vacuum wavelength ? to a resonant cavity thereof to satisfy the relationship: W??/10 where a substrate tube is located within the resonant cavity and plasma chemical vapor deposition deposits layers of doped silica thereon followed by thermal collapsing the substrate and drawing an optical fiber therefrom.

Abstract: A method of making an optical waveguide preform includes forming a preform including a first portion and a second radial portion, wherein the second portion includes a dopant, and wherein the first portion exhibits a density greater than the second portion. The method further includes stripping at least a portion of the dopant from the second portion. In a preferred embodiment, the stripped dopant has migrated in a previous processing step.

Abstract: In a known method for producing an SiO2 blank, SiO2 particles are formed in a burner flame assigned to a deposition burner and are deposited under the effect of an electrical field on a deposition surface of a carrier rotating about its longitudinal axis, said at least one deposition burner being reciprocated in a predetermined sequence of movement along the developing blank between turn-around points. Starting from said method, in order to obtain blanks of a predetermined, in particular axially homogeneous, density and mass distribution, it is suggested according to the invention that the geometrical shape of the burner flame should be varied by the electrical field in dependence upon the position of the deposition burner during the sequence of movement.

Abstract: A method for adjusting a photosensitive optical waveguide having an optical path length to a stabilized desired optical path length. The method includes the step of changing the optical path length of the photosensitive optical waveguide by exposing at least a first portion of the waveguide to actinic radiation and creating an induced index change in the exposed first portion. The waveguide then is subjected to an annealing cycle that stabilizes the waveguide. After the step of stabilizing the waveguide, the optical path length is adjusted by subjecting at least a selected part of the exposed first portion of the waveguide to a localized heating sufficient to change the refractive index at the selected part until the desired optical path length is achieved.

Abstract: The present invention relates to a method of making a soot particle and apparatus for making such soot particle. Preferably the method of making the soot particle is substantially free of the step of combusting a fuel and substantially free of the step of forming a plasma. Preferably, the apparatus is devoid of a heating element associated with both combustion and formation of a plasma. A preferred technique for at least one heating step for forming the soot particle is induction heating.

Abstract: The present invention is a manufacturing method for an optical fiber grating which can decrease the light intensity at the bottom wavelength in the reflection or transmission spectrum to be sufficiently small. This method is comprised of a grating creation step and a phase adjustment step. The grating creation step is a step of creating a plurality of grating sections with different Bragg wavelengths arrayed in series in the longitudinal direction of this optical fiber, sandwiching the phase adjustment sections on an optical fiber made of a material which induces a light induced refractive index change phenomena. The phase adjustment step is a step of adjusting the light intensity at the bottom wavelength in the reflection or transmission spectrum of this optical fiber grating by irradiating the ultraviolet light only to the phase adjustment section while monitoring the transmittance or reflectance spectrum of the optical fiber grating after the grating step.

Abstract: A method of producing with the collapsing process an optical fiber preform capable of forming an optical fiber in which an increment in transmission loss due to OH absorption is reduced, and an optical fiber preform and an optical fiber produced with the method. The method comprises reducing the amount of hydrogen atom-containing substances in a glass pipe, sealing one end of the glass pipe, and collapsing the glass pipe to obtain a solid body. One aspect of the method comprises heating the glass pipe at 550° C. or below, sealing one end of the glass pipe, and collapsing the glass pipe to obtain a solid body. The preform produced with the method has a feature in that its portion formed by the interface portion at the time of the collapsing contains OH groups at a concentration of 100 wt. ppb or below. The optical fiber produced by drawing the preform has a feature in that its OH-originated loss is less than 0.5 dB/km at a wavelength of 1.38 &mgr;m.

Abstract: A method for increasing the photosensitivity of a selected portion of an optical fiber and for producing a grating in the selected portion of an optical fiber. The method includes the step of placing the selected portion of the optical fiber in a hydrogen containing atmosphere. The volume of the hydrogen-containing atmosphere immediately surrounding only the selected portion of the optical fiber is heated to a temperature of at least 250° C. Only the selected portion of the optical fiber is exposed to the heated volume of the hydrogen-containing atmosphere at a temperature of at least 250° C. for a predetermined time.

Abstract: Disclosed is a method for fabricating an optical fiber block, in which a cover formed from glass is bonded onto a substrate, the top of which is provided with one or more grooves. The method comprising the steps of: heating the cover to a predetermined temperature; and applying an electric field so that electrostatic attraction is generated in the interface of the cover and the substrate in the state in which the heated cover is being seated on the top of the substrate, thereby bonding the cover and the substrate.

Abstract: A process for forming an integrated optical device in a substrate, comprising the steps of: providing a substrate having a base index of refraction; providing a UV light beam; focusing the beam on a portion of the substrate in order to form a region of increased refraction; and scanning an elongated region of the glass substrate with the beam in order to define at least one elongated optical channel having an increased index of refraction relative to the base index of refraction, the elongated optical channel for guiding light transmitted there along. The process further includes: forming a plurality of elongated optical channels in the substrate, wherein a first optical channel is operative for transmitting light to the plurality of elongated optical channels such that the transmitted light is divided among the plurality of elongated optical channels, thereby forming an optical beamsplitter.

Abstract: The present invention provides a method for reducing the density of sites on the surface of fused silica optics that are prone to the initiation of laser-induced damage, resulting in optics which have far fewer catastrophic defects and are better capable of resisting optical deterioration upon exposure for a long period of time to a high-power laser beam having a wavelength of about 360 nm or less. The initiation of laser-induced damage is reduced by conditioning the optic at low fluences below levels that normally lead to catastrophic growth of damage. When the optic is then irradiated at its high fluence design limit, the concentration of catastrophic damage sites that form on the surface of the optic is greatly reduced.

Abstract: The present invention includes a method of making a preform for an enhanced photosensitive fiber comprising depositing successive layers of optical material the inside a tube using modified chemical vapor deposition, and collapsing the layers of optical material in a reducing atmosphere with a positive pressure. The present invention also includes a method of making an enhanced photosensitive fiber comprising making a preform using modified chemical vapor deposition wherein the preform is collapsed in a reducing atmosphere with a positive pressure and drawing the preform into a fiber.

Abstract: Waveguides are fabricated in a variety of silicate glasses by applying electric fields to a substrate at elevated temperatures. The glass has components of at least two alkali or alkaline earth ions with differential mobility rates. A DC electric field is applied to the glass which separates the mobile cations into regions according to their mobility. Each region presents a different refractive index, allowing a waveguide to be formed. This method has been used to produce waveguides with an index increase greater than 10−2 in soda-lime glass with no external ion source, and the waveguides are buried beneath the substrate surface without an additional step. Waveguides, lenses or other devices requiring spatial variation of refractive index profile can thus be formed by redistribution of ions already in the glass, rather than by supplying ions from an external source.

Abstract: A method of forming a hybrid optical component includes the steps of masking and etching a pattern on a core layer of a planar optical component to define at least one alignment element and an optical element and subsequently overcladding the optical element such that a passive platform is formed which exposes a surface of the optical element such as a waveguide and an alignment element for receiving a mirror image alignment element formed on an active platform including an active device, such as a laser. Hybrid components include a passive platform having an alignment element formed therein and a waveguide for receiving an active platform with a mating mirror image alignment element and an active device which aligns with the waveguide when the platforms are mated.

Abstract: An optical waveguide component has a first optical member in which a predetermined first core pattern groove is formed and a second optical member in which a predetermined second core pattern groove is formed, the first and second optical members being combined together so that said first and second core pattern grooves are opposingly overlapped with each other, and the first and second core pattern grooves being filled with a core material.

Abstract: A process of poling a silica material such as an optical fiber whereby electro-optic non-linearities are induced so that the material can function as a phase modulator and switch in optical communications applications. The poling is effected at an elevated temperature on the order of 450° C. or higher, using an electric field on the order of 800 V/&mgr;m or higher for a period of time in the range of one minute to several tens of minutes.

Abstract: A method and apparatus for manufacturing optical components. A burner generates soot, and a surface area collector collects the soot. The burner is disposed such that the soot collected within the surface area collector is substantially not reheated by subsequently deposited soot. Magnetic forces direct the soot to desired location(s) within the surface area collector. The surface area collector operates at relatively low temperatures sufficient to retain rather volatile substances, such as fluorine, in the soot.

Abstract: A processing method of a silica glass fiber, which is applicable to a long fiber, to improve its UV resistance by UV irradiation and heat treatment. Initially, a heating furnace 1 is positioned such that the left end of the silica glass fiber is within the heating furnace 1. Then, the heating furnace 1 is moved toward the right, while UV is irradiated with a UV source to the left end surface of the silica glass fiber. Since the silica glass becomes transparent due to removal of structural defects that have been caused by the UV irradiation, the UV travels further forward and causes other structural defects there. When the heating furnace 1 is moved there, the structural defects are removed and the silica glass fiber becomes transparent. By repeating these steps, the fiber is processed throughout length. Thus, mass production becomes possible and an improvement of productivity and lower costs can be achieved.

Abstract: An optical fiber for maximizing residual mechanical stress and an optical fiber grating fabricating method using the optical fiber are provided. The optical fiber includes a core formed of silica, for propagating light, and a cladding formed of boron-doped silica, surrounding the core. Alternatively, the optical fiber includes a core formed of phosphorous-doped silica and a cladding formed of silica, surrounding the core.

Abstract: A process for producing a synthetic quartz glass for an optical member, which comprises a step of irradiating a synthetic quartz glass having an OH group content of 50 ppm or lower with vacuum ultraviolet light having a wavelength of 180 nm or shorter to improve the transmittance in a region of wavelengths of not longer than 165 nm.

Abstract: A method for heating optical fibers by electric discharge includes fusion splicing optical fibers and then applying a heating to a neighborhood of a fusion splicing part of the optical fibers by the electric discharge. The discharge electrodes are provided in a direction perpendicular to the plane in which the optical fibers are arranged. The heating is applied to the neighborhood of the fusion splicing part by the electric discharge with discharge electrodes. The discharge electrodes are moved not only in a direction of arrangement of the optical fibers but also in an axial direction of the optical fibers such that more thermal energy is applied to an optical fiber positioned closer to a center of the arrangement of the optical fibers than to an optical fiber positioned away from the center.

Abstract: The present invention relates generally to UV (ultraviolet) photosensitive bulk glass, and particularly to batch meltable alkali boro-alumino-silicate and germanosilicate glasses. The photosensitive bulk glass of the invention exhibits photosensitivity to UV wavelengths below 300 nm.

Abstract: A method of optical fiber preparation includes concurrently processing a plurality of optical fibers which have a substantially vertical orientation, and the concurrent processing is substantially automated.

Abstract: A method for increasing the photosensitivity of a selected portion of an optical fiber and for producing a grating in the selected portion of an optical fiber. The method includes the step of placing the selected portion of the optical fiber in a hydrogen containing atmosphere. The volume of the hydrogen-containing atmosphere immediately surrounding only the selected portion of the optical fiber is heated to a temperature of at least 250° C. Only the selected portion of the optical fiber is exposed to the heated volume of the hydrogen-containing atmosphere at a temperature of at least 250° C. for a predetermined time.

Abstract: An optical fiber is prepared by applying a liquid electron beam-curable resin composition to a bare optical fiber or a coated optical fiber having a primary or secondary coating on a bare optical fiber, irradiating electron beams to the resin composition on the optical fiber for curing while the optical fiber passes a zone under substantially atmospheric pressure, and providing a magnetic field and optionally an electric field in the zone for thereby improving the efficiency of electron irradiation. The method can comply with the increased drawing speed of the bare optical fiber and does not detract from the transmission properties of the optical fiber.

Abstract: A thermoplastic resin composition comprises a compatible resin blend of a polyester sulfonate salt ionomer and a polyamide and at least one difunctional epoxy compound having at least one cyclohexane ring moiety and two terminal epoxy functional groups, wherein at least one of the two terminal epoxy functional groups is a substituent on the at least one cyclohexane ring moiety; and, optionally, a catalyst compound or rubber impact modifier.

Abstract: An apparatus and method for manufacturing chiral fibers having chiral fiber Bragg gratings properties from UV sensitive optical fibers by using a UV laser beam to impose a chiral modulation of the refractive index at the core of the fiber.

Abstract: Based on a known process for the manufacture of opaque quartz glass, by mixing SiO2 particles and an additive which is volatile at a melting temperature, forming a body and melting said body with an advancing melt front forming in the body, it is proposed according to the invention that in order to reduce the danger of contamination, a body (1) be formed with an inner bore (6) and be heated in such a manner that the melt front (10) advances from the inner bore (6) to the outside. The article of pure opaque quartz glass according to the invention has high resistance to temperature change, high mechanical strength and good chemical durability. It is distinguished by an opening (6) enclosed by an inner wall (9), with an inner SiO2 surface layer (15) having a layer thickness ranging from 30 mm to 500 mm and a density of at least 2.15 g/cm3.

Abstract: There is disclosed a method of constructing photosensitive waveguides on silicon wafers through the utilization of a Plasma Enhanced Vapor Deposition (PECVD) system. The deposition is utilized to vary the refractive index of resulting structures when they have been subject to Ultra Violet (UV) post processing.

Abstract: The present invention provides a method for reducing the density of sites on the surface of fused silica optics that are prone to the initiation of laser-induced damage, resulting in optics which have far fewer catastrophic defects and are better capable of resisting optical deterioration upon exposure for a long period of time to a high-power laser beam having a wavelength of about 360 nm or less. The initiation of laser-induced damage is reduced by conditioning the optic at low fluences below levels that normally lead to catastrophic growth of damage. When the optic is then irradiated at its high fluence design limit, the concentration of catastrophic damage sites that form on the surface of the optic is greatly reduced.

Abstract: The present invention relates generally to UV (ultraviolet) photosensitive bulk glass, and particularly to batch meltable alkali boro-alumino-silicate glasses. The photosensitive bulk glass of the invention exhibits photosensitivity to UV wavelengths below 250 nm.

Abstract: An optical waveguide substrate, which has less particles or concave pits caused by Oxidation Induced Stacking Fault on the quartz film when oxidizing the surface of the silicon substrate relatively thickly and forming on its surface a quartz film to become an optical waveguide, is manufactured. The making method of the optical waveguide substrate comprises a step of exposing a silicon substrate to an atmosphere of oxidizing gas while heating to form a quartz film on the surface thereof for an optical waveguide, characterized in that a density of Oxygen contained in said silicon substrate is 24 ppma at maximum.

Abstract: A silica glass is provided for use in an optical system processing an excimer laser beam. The silica glass has a molecular hydrogen concentration of about 5×1018 molecules/cm3 or less and is substantially free from defects which become precursors susceptible to an one-photon absorption process and a two-photon absorption process upon irradiation of the excimer laser beam to the silica glass.

Abstract: Voltage is applied between electrodes (14a, 14b) under UV irradiation to perform a UV excitation poling, thereby producing microcrystal particles at a core unit (10a). Accordingly, second-order optical nonlinearity is developed at the core unit (10a) of an optical fiber (10). Under a high-temperature condition, a second-order optical nonlinearity can be imparted by a comparatively low-voltage UV excitation poling when a second-order optical nonlinearity decreases.

Abstract: A process of poling a silica material such as an optical fiber whereby electro-optic non-linearities are induced so that the material can function as a phase modulator and switch in optical communications applications. The poling is effected at an elevated temperature on the order of 450° C. or higher, using an electric field on the order of 800 V/&mgr;m or higher for a period of time in the range of one minute to several tens of minutes.

Abstract: A method for shaping an end of an optical fiber having a core to provide a novel optical fiber (or waveguide) includes the steps of contacting the fiber against a mold having a predetermined shape, The fiber and/or mold is heated. The fibers can be made of silica. The method is well suited for making wedge-shaped (i.e., standard screwdriver-like shaped) fiber tips. In addition, an apparatus for molding a shaped tip precisely located with respect to a core of an optical fiber includes a mold having one or more surfaces of the mold being configured and dimensioned to impart a predetermined shape to an end of an optical fiber contacted therewith, the predetermined shape being precisely located with respect to the core of the optical fiber.

Abstract: A processing method of a silica glass fiber, which is applicable to a long fiber, to improve its UV resistance by UV irradiation and heat treatment. Initially, a heating furnace 1 is positioned such that the left end of the silica glass fiber is within the heating furnace 1. Then, the heating furnace 1 is moved toward the right, while UV is irradiated with a UV source to the left end surface of the silica glass fiber. Since the silica glass becomes transparent due to removal of structural defects that have been caused by the UV irradiation, the UV travels further forward and causes other structural defects there. When the heating furnace 1 is moved there, the structural defects are removed and the silica glass fiber becomes transparent. By repeating these steps, the fiber is processed throughout length. Thus, mass production becomes possible and an improvement of productivity and lower costs can be achieved.

Abstract: A method and apparatus for controlling the shape and position of a deformable object are described. At least a portion of an object is heated to a temperature sufficient to render the heated portion deformable by a force. An image profile of the heated portion of the object is obtained. A controller compares the image profile to a reference profile and produces an error image signal. Based on the error image signal, an instruction signal is generated. A force applicator responsive to the instruction signal applies a radial force to at least one distinct predetermined location on the heated portion of the object in response to the instruction signal to cause the heated portion of the object to conform to the reference profile. The invention is particularly useful in controlling the shape of an optical fiber preform.

Abstract: A method for rapidly increasing the photosensitivity of an optical fiber comprising the step of providing an optical fiber comprising a glassy material and a thermally-stable coating. The thermally-stable coating has a thermally-stable exposure band, wherein desired time/temperature exposure parameters fall within the time/temperature thermal stability exposure band for the coating. The optical fiber is exposed for the desired time/temperature exposure to a hydrogen-containing atmosphere. The desired temperature is more than 250° C. and the desired time exposure does not exceed one hour. The glassy material then may be irradiated with actinic radiation, such that the refractive index of the irradiated portion results in a normalized index change of at least 10−5.

Abstract: A method of manufacturing an optical fiber using silica glass having properties changed by UV irradiation and heat treatment, which method facilitating efficient mass production of long optical fibers. A base material of silica glass is heated in a fiber spinning heating furnace, and a silica glass fiber is drawn out of the forward end of the heating furnace to be spun up. In a UV irradiation zone, UV is irradiated to the spun silica glass fiber. As a result, multiple structural defects are caused in the silica glass fiber. When the structural defects are removed by heat treatment, the average bond angle of Si—O—Si network in the silica glass increases compared with that before heat treatment, and structural relaxation proceeds to provide a structurally stable glass, in which generation of defects due to further UV irradiation is hindered. Thus, a silica glass fiber having high UV resistance is obtained.

Abstract: A silicon surface oxidation device utilizes a steam generator in which heated water is barely in contact with the members of the device, steam with no contamination is efficiently generated, and the silicon surface can be oxidized through relatively large thickness by using a steam oxidation method which is simple and high in safety. The steam generator has a feed port for pure water which flows along a surface in a chamber, an oscillator for oscillating a microwave toward the surface, a steam exit port for sending out the steam of the pure water generated from the surface by the microwave, and a discharge port for the pure water flowing along the surface. A heating furnace is connected to the steam exit port, and silicon placed in the heating furnace is oxidized by the steam generated by the microwave.

Abstract: A wavelength selective optical fiber coupler having various applications in the field of optical communications is disclosed. The coupler is composed of dissimilar waveguides in close proximity. A light induced, permanent index of refraction grating is recorded in the coupler waist The grating filters and transfers energy within a particular range of wavelengths from a first waveguide to a second waveguide. Transversely asymmetric gratings provide an efficient means of energy transfer. The coupler can be used to combine or multiplex a plurality of lasers operating at slightly different wavelengths into a single fiber. Other embodiments such as a dispersion compensator and gain flattening filter are disclosed.

Abstract: The present invention is a process for manufacturing an optical fiber Bragg grating, which in a preferred embodiment includes the steps of: (a) removing at least a portion of a removable coating on an optical fiber element in at least one predetermined section to sufficiently expose the optical fiber in the section for a subsequent treatment by a source of optical radiation; (b) fixing the at least one section with respect to the source of optical radiation; (c) directing optical radiation from the source into the optical fiber to produce at least one Bragg grating in the at least one section; and (d) covering the at least one section. The present invention also extends to an apparatus for carrying out the process steps described above, which includes means for coating removal, means for fiber immobilization, means for writing a Bragg grating, and means for packaging.

Abstract: A simple method for producing a synthetic quartz glass having excellent homogeneity and high transmittance, which is useful as an optical material in producing steppers equipped with an ArF excimer laser as a radiation source. A method for producing a synthetic quartz glass for use in ArF excimer laser lithography, which comprises irradiating a highly homogeneous synthetic quartz glass containing less than 60 ppb of Na with ultraviolet radiation having a maximum wavelength of 260 nm for not less than the duration expressed by the equation: Y=(80X−1880)/Z wherein X represents an Na concentration (ppb), Y represents the duration of irradiation (hours), and Z represents the illuminance of an ultraviolet radiation on an irradiated surface (mW/cm2).

Abstract: Radiation-curable compositions, having high elongation at break and toughness after cure can include the following pre-mixture components: a) a polymer, oligomer or monomer having at least one (meth)acrylate functional group; b) an oligomer or monomer, exclusive of (meth)acrylate functional groups, having an ethylenically unsaturated functional group; and c) an elongation promoter; wherein the composition, after radiation-cure, has an elongation at break of at least about 200%. Glass substrates and optical fibers are coated with the radiation-curable composition. Monofilament fiber or a plurality of fiber filaments, such as sewing thread, are coated with the radiation-curable binder composition, which after cure, demonstrates high elongation at break.

Abstract: A technique is described for the formation of nano and micro-scale patterns and optical wave-guides, by using Bipolar Electrochemistry. Atoms are deposited or removed from a surface by creating and moving ions into or out of a medium by the use of electric fields, currents, and induced surface charges. To improve the deposition process, lasers, electron, and ion lenses can be positioned over the surface being deposited to further define the pattern being created. This technique does not harm the surface or crystal lattice of the substrate being deposited on and is powerful enough to transport dopants completely through a substrate. The technique can be used to expose electron beam activated resist which can be used in traditional fabrication processes or to create wave-guides connecting separate optical or electro-optical devices together. As a result smaller and newer types of integrated circuits, electronic devices, and micro machines can be fabricated.

Abstract: To manufacture polarization-maintaining optical fibers, a fiber is directly and continuously irradiated with at least one beam of UV radiation during drawing and before application of external coatings.

Abstract: A method for fabricating an optical waveguide, comprising the following steps. That is, forming an optical waveguide on surface of a substrate via an atmospheric pressure chemical vapor deposition (AP-CVD) method using a silica raw material containing an organic material, and irradiating ultraviolet light on at least a portion of that optical waveguide. The refractive index of the portion of the optical waveguide irradiated with ultraviolet light increases. Since changing the refractive index in this way enables the formation of a diffraction grating, it is possible to manufacture optical filters and wavelength dispersion devices.

Abstract: An apparatus and method used in manufacturing a long period grating filter are provided. The apparatus used in manufacturing a long period grating filter includes an upper body including a plurality of teeth spaced from each other by a predetermined distance and a lower body having teeth spaced from each other by the same distance as the teeth of the upper body and a plurality of grooves in a direction perpendicular to the teeth in which an optical fiber is loaded, wherein the upper and lower bodies are engaged with each other, and a plurality of grooves are formed in the loaded optical fiber by abrading the loaded optical fiber by moving the upper body in a direction parallel to the teeth. According to the present invention, an excimer laser, various other expensive equipment, and an optical fiber sensitive to ultraviolet rays are not required for manufacturing the long period grating filter. Accordingly, complicated hydrogen processing is not necessary.

Abstract: Optical plates which have columnar features approximately in the direction of light propagation which are capable of total internal reflection, a controllable numeric aperture (NA) at input and output surfaces, rotational azimuthal averaging and translation of the object plane from a back surface of the plate to a front surface of the plate and are optical equivalent of a FOFP. These plates are made from a composition of irradiation sensitive glass which has been etched in either the columnar features or the surrounding features. If the surrounding features have been etched, the etched areas are filled with either a low melt glass or plastic or a light blocking material such as a black composition material. If the columnar features have been etched the etched areas are filled with a low melt glass or plastic.