Showing papers on "Hard-clad silica optical fiber published in 1986"

Pressure or strain sensitive optical fiber

Abstract: Pressure or strain sensitive optical fiber having a core, at least a portion of which has a predetermined refractive index for transmitting light therethrough, a cladding adjacent the core having a refractive index which is less than that of the core, and a concentric light transmissive layer adjacent the cladding having a refractive index which is greater than that of the cladding. The light transmissive layer has an internal diameter which is greater than the unperturbed mode boundary diameter of the core, such that all light passes through the core when the fiber is unperturbed. When the optical fiber is subjected to pressure forces in the form of stress or strain, light passes through the light transmissive layer in proportion to the amount of stress or strain acting upon the fiber. Also, pressor sensors and methods for measuring forces or pertubations utilizing such optical fiber.

Fiber optic dropwire

Abstract: A fiber optic dropwire having a fiber optic transmission member between two strength members. The optical fiber has an outer coating having a higher melting point than the outer dropwire covering.

Multimode fiber optic coupler and method for making

Abstract: A multimode fiber optic coupler includes a first multimode optical fiber having a core and cladding surrounding the core and having a first longitudinal segment in which the cladding has been substantially removed exposing the core and in which a portion of the exposed core forms a first biconical taper segment; a second multimode optical fiber having a core and a cladding surrounding the core and having a second longitudinal segment in which the cladding has been substantially removed exposing the core and in which a portion of the exposed core forms a second biconical taper segment; and a coupling region formed by portions of the first and second biconical taper segments being fused together in parallel juxtaposition with one another.

Hermetic coatings for optical fiber and product

Abstract: A method for hermetically sealing a silica based fiber product after the fiber product has been drawn from a melt or preform wherein a hermetic layer of boron carbide or a ceramic compound having a density of above about 4 g/cc is deposited upon the fiber product. The fiber product can be initially coated with carbon or boron carbide prior to the application of the ceramic compound. Also, a method for making such fiber products using these methods, and the resultant hermetically sealed fiber products produced thereby.

Fiber optic rotary switching device

Abstract: A fiber optic rotary switching device having a single optical fiber rotatable between a plurality of optical fibers. The arrangement for rotating the single optical fiber is designed such that the single optical fiber flexes but does not twist with respect to an end thereof which is fixed to a light source (or, in the alternative to a light detector). As a result, the switching device switches light passing through the single optical fiber to a preselected one of the plurality of optical fibers while simultaneously preventing extraneous light from reaching the other optical fibers.

High strength, heavy walled cable construction

Abstract: An optical fiber is surrounded by a protective cladding of a liquid crystal material and fabricated by passing the optical fiber through a die member which operates to deposit relatively thin individual high-strength layers built up to a desired thickness. In another embodiment, the desired thickness is achieved by surrounding the optical fiber or fibers with a plurality of individual high-strength strands of liquid crystal polymer collectively compressed about the optical fiber(s).

Optical fiber termination including pure silica lens and method of making same

Abstract: A single mode fiber expanded beam termination is formed by fusion splicing an undoped (pure) silica rod to a single mode fiber. The length of the rod controls the expanded beam diameter, and forms a lens on the free end of the undoped silica rod to collimate an output beam.

Coupler fabrication techniques for dissimilar fibers

Abstract: A fused twin biconical taper fiber optic splitter comprised of a pair of non-identical monomode or nominally monomode optical fibers having predetermined cladding diameters fused at respective narrowed waists, the cladding diameter of one fiber before coupler fabrication being greater than the other, whereby wavelength selective coupling between one and the other fiber is obtained.

Technique and apparatus for fabricating a fiber Fabry-Perot etalon

Abstract: A practical, manufacturable Fabry-Perot etalon and method for fabricating the same is disclosed. The plastic coating material is removed from the ends of a predetermined length of single mode fiber. A small area of the glass fiber is exposed by scraping away the coating near the center of the fiber on one side, and the fiber is then broken at this point forming a small gap. The remaining coating holds the broken fiber together and automatically matches the pieces in alignment. Mirrors of desired relfectivity are applied to the polished fiber ends, either by gluing on discrete mirrors or by applying multilayer dielectric coatings. The fiber/mirror structure is mounted onto a piezoelectric substrate. A voltage is applied to the piezoelectric substrate, causing longitudinal expansion of the fiber gap and providing the scanning means to obtain a spectrum of resonant wavelengths.

Method for producing elastomeric optical fiber

Abstract: @ An elastomeric optical fiber comprising a core made of an elastomer with rubbery elasticity and a cladding surrounding the core and having low attenuation of light transmission is produced by a method comprising flowing down a liquid polymer for the core with cross-linking it, and simultaneously with or after the formation of the core, providing the cladding around the core.

Plastic optical fiber and process for producing the same

Abstract: A plastic optical fiber which is superior in the light transmission characteristics, particularly in those within a visible light region and also superior in heat resistance, and a process for producing the same are provided, which plastic optical fiber comprises a polycarbonate as its core material and a polymer as its cladding material having a refractive index lower than that of the core material, wherein the relationship between the light transmission loss L 500 (dB/km) of the fiber as measured at a wavelength of 500 nm and that as measured at 660 nm being expressed by the following inequality: L.sub.500

Plastic optical fiber star coupler.

Abstract: A new plastic optical fiber star coupler and the means of fabricating it have been developed. This coupler has been realized by twisting and pulling the waist region of a biconical tapered fiber bundle made by pretapered fibers while heating. Controlling the biconical tapered shape has been achieved by jetting gas on the fiber surface while heating the fiber bundle. By using this fabrication method, the desired diameter mixing portion can be formed without breakage from melting. Low-cost optical star couplers with large port number, low excess loss, and small power deviation can be obtained.

Optical fiber-device interconnection and method

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.

Method for coating optical waveguide fiber

Abstract: In the process for applying a protective plastic coating to a glass optical waveguide fiber by the application of a curable liquid coating material thereto and the subsequent curing of the liquid coating to a protective plastic layer, the surface of the glass optical fiber is conditioned prior to the application of the liquid coating material thereto by replacing air adjacent the fiber surface with a selected gas preferably exhibiting high solubility in the liquid coating composition and resisting bubble formation in the liquid coating layer as it is formed.

Method for producing multi-core optical fiber

Abstract: A multi core optical fiber in which the core distances between the adjacent elemental optical fibers are substantially the same is produced by a method for producing a multi core optical fiber, comprising sustaining upper ends of plural optical fiber preforms (3) each comprising a core and a cladding so that distances between the adjacent preforms are substantially the same, melting the other ends of the preforms and simultaneously drawing the preforms whilst applying a constant tension.

Depressed cladding optical fiber cable

Abstract: An optical fiber cable (20) includes a core (21) comprising plurality of units (22--22). Each unit is formed by a plurality of optical fibers (24--24) which are assembled together without intended stranding. Each of the optical fibers includes a core, and inner and outer claddings with the inner cladding characterized by an index of refraction depressed from that of the outer cladding. The ratio of the inner cladding diameter to the core diameter and the ratio of the difference in the indices of refraction of the inner and outer claddings to the difference in indices of refraction between the core and the inner cladding are such that each optical fiber is capable of operation in a single mode fashion at a predetermined wavelength. Also, the difference between the indices of refraction of the core and the inner cladding is sufficiently high to cause each fiber to be substantially insensitive to microbending. The plurality of units are enclosed in a common tube (34) which provides a predetermined packing density. In one embodiment, a waterblocking material (46) is disposed within the tube to fill the interstices between the optical fibers and between the units. The waterblocking material is such that its critical yield stress does not exceed about 70 Pa at 20° C. and such that it has a shear modulus of less than about 13 KPa at 20° C. The common tube is enclosed with a sheath system. This arrangement is such that the optical performance of the cable is not degraded at temperatures as low as -40° F.

Contact for terminating an optical fiber

Abstract: An optical fiber contact for terminating an optical fiber includes a solid multi-part thermoset mixture in a cavity in a front portion of the contact, an optical fiber being terminated by heating the thermoset so as to cause it to soften and liquify and subsequently inserting an optical fiber through the contact. The thermoset when liquified chemically reacts so as to form an epoxy adhesive which secures the optical fiber within the contact and keeps the optical fiber in place even when subjected to extremely wide temperature variations.

Fiber optic phosphor screen and a method of manufacturing the same

Abstract: A phosphor screen constructed by forming a phosphor layer on one side of an optical fiber plate consisting of a large number of bundled single optical fibers, each of which fibers comprises a cylindrical core and a clad surrounding the curved surface of the fiber core. At least that side of the respective fiber cores which faces the phosphor layer is removed, to provide a depression. Sufficiently large spaces are formed between the fiber cores and phosphor layer, to prevent both members from being brought into optical contact with each other.

Optical waveguide glass fiber flame processing

Abstract: In the interest of reducing the effect on tensile strength of flame processing of a silica-based optical fiber waveguide, such processing is by a method in which a significant flow of oxygen surrounds a flame produced by combustion of hydrogen, deuterium, ammonia, or deuterated ammonia. Flame processing may be for purposes such as, e.g., fiber drawing, fiber fusing for the sake of lateral coupling, refractive index modification by the diffusion of dopants, and fiber splicing in the manufacture of long lengths of fiber. Even though there is no use of chlorine, at least 80 percent of spliced fibers have a tensile strength greater than or equal to 500 kpsi (3.45 GPa) as is desirable in optical fiber cable manufacture.

Optical multiconductor of silica glass type

Abstract: OF THE DISCLOSURE1. An optical multiconductor of the silica glass type chracterized in that the multiconductor comprises 102 to 107 optical fibers of the silica glass type fused to one another, each of the optical fibers comprising a core made of doped silica glass and occupying at least 20% of the fiber in cross sectional area, and a cladding layer made of a kind of silica glass and formed on the core, the core having a refractive index distribution satisfying the following expression:n2?n1 -1 0.50(n1 - n1) where-in n0 is the refractive index of the core at its center, n1 is the refractive index of the core at its outermost portion, and n2 is the refractive index of the core at a position centered about the axis of the core and having an average radius of 0.65r1, the r1 being an average radius of the core. The multiconductor is suited to use as the image trans-mitter of an image scope for industrial, medical or other uses.

High power, high intensity CO infrared laser transmission through As2S3 glass fibers

Abstract: Optical power transmission of 5‐μm band CO laser beam through As2S3 glass core Teflon fluorinated ethylene propylene clad fibers is described. The maximum transmitted power is as high as 62 W with a 700‐μm core diameter fiber, which corresponds to a power intensity of 16 kW/cm2 at the fiber output end. The influence of fiber bending on the transmission characteristics is also reported.

Optical fiber cable with hydrogen combining material therein

Abstract: Optical fibers of an optical fiber, telecommunication cable are protected with respect to hydrogen by including in the cable a mixture of molybdenum trioxide and a catalyst selected from the transition metals, the inorganic and organic compounds of the transition metals and the organometallic acids of the transition metals, such mixture being used by itself or being supported by inert materials. The mixture may surround the fiber or fibers, be applied as a coating on a component of the cable, be incorporated in a component of the cable or be included in a rod or tube adjacent to the fiber or fibers and within the cable sheath.

Compressed fiber optic cable

Abstract: A fiber optical cable for conducting light along its length. The cable is composed of a plurality of transparent polymer fibers. The fibers are formed by drawing the heated viscous polymer from an orifice. In pulling the softened fiber, the polymer molecules become aligned parallel to the sides of the polymer fiber. A surface coating of a lower refractive index transparent polymer is applied. The optical fibers are arranged in the desired order and heated and softened. Pressure is applied against the sides of the heated and softened fiber optic cable compressing the round polymer optical fibers to form fibers having flat sided geometric shapes to eliminate the open spaces and voids between the optical fibers.

Optical fiber junction and method of making same

Abstract: There are disclosed an optical fiber junction device and a method of making the same. The method comprises the steps of providing a central inner pipe or rod of glass, arranging a plurality of optical fibers around the inner pipe or rod, and externally heating the optical fibers and the central inner pipe to form a thermally fused assembly having cores of a sectorial cross section. The inner pipe may include a tapered portion having a reduced diameter. The optical fibers may comprise optical fiber junction units each composed of a plurality of optical fibers.

Multi-Hundred-Fiber Cable Composed of Optical Fiber Ribbons Inserted Tightly into Slots,

Abstract: : A new type of cable assembly with a multitude of optical fibers is proposed and developed for use in subscriber loops. Optical fiber ribbons are tightly inserted into helically shaped rectangular slots on a polyethylene rod. Optical fiber ribbon and slot structures are investigated to minimize optical loss increase. Fiber coating and ribbon stranding structure design methods are presented. Fiber strains, especially a residual strain, are investigated. It is found that a residual strain is restricted to less than 0.05 % by selecting helical pitch of the slots as 700 mm or more to guarantee a required fiber life-time. Based on the design, 600-fiber cables are manufactured. It is demonstrated that the cables have excellent transmission properties through the mechanical and thermal tests and field trials. (Author)

Deposition of Piezoelectric Films on Single-Mode Fibers and Applications to Fiber Modulators

Abstract: Techniques are described by which an oriented, piezoelectric zinc oxide film is sputtered directly on one side of an 80-pm-diameter fused silica single-mode fiber. These techniques have been used to fabricate piezoelectric transducers in the GHz frequency range. Acoustic t ransducers fabri cated directly on a fiber produce fields focused on the fiber core for efficient acousto-optic interaction, making possible many new all-fiber modulators and taps. An all-fiber phase modulator with a center frequency of approximately 850 MHz is demons t ra t ed. 0.5-5

Optical fiber having glass core and fluoro-copolymer cladding

Abstract: The invention relates to an optical fiber of the step-index type using quartz glass or an inorganic optical glass as the core material and a fluorine-containing resin as the cladding material. A copolymer of vinylidene fluoride with hexafluoroacetone, preferably at a molar ratio in the range from 96:4 to 88:12, is employed as the cladding material. Using such a copolymer, a highly transparent and very strong and tough cladding layer can easily be formed by a solution coating method.

Scattering loss measurement for small segments of fluoride optical fibers

Abstract: A new light scattering measurement system for optical fibers has been developed. It is intended for measuring 3-D scattered light intensity distribution from a short fiber segment. Using this system, it has been verified for the first time that ZrF4-based fluoride optical fiber exhibits a Rayleigh scattering characteristic and has lower scattering loss than silica fiber.

Metal Coated Fibers

Abstract: Hermetically-coated optical fibers have been fablicated with aluminum coating using metal dipping method. Mechanical and optical properties of the fibers have been investigated for high temperature applications. Mechanical aging test have been performed at the temperature from 300°C to 400°C by static fatigue mandrel test. Aluminum coated fibers have been proved their fatigue resistivity, there have been no problem at 350°C continuous exposure. Optical aging test have been performed from room temperature to 600 °C. Several kinds of aluminum coated fibers which include different core material or different combination of core and cladding material, have been tested and loss spectra have been evaluated. Ultra-violet absorption tail and OH-absorption peaks appeared in all fiber when heating, but their magnitude and influences for application wavelength seems quite different. In silica core fiber, two absorption increase is small, so that, there is no influences of loss increase at 0.85 μm band. In germanium doped fiber, loss caused by the defect center must be converted to the stable permanent OH when high temperature application.