Abstract: Provided is a method of manufacturing an optical fiber preform from which an optical fiber having the desired characteristics can easily be produced.

Abstract: Ceramics comprising (i) at least one of Nb2O5 or Ta2O5 and (ii) at least two of (a) Al2O3, (b) REO, or (c) at least one of ZrO2 or HfO2. Embodiments of ceramics according to the present invention can be made, formed as, or converted into optical waveguides, glass beads, articles (e.g., plates), fibers, particles (e.g., abrasive particles), and thin coatings.

Abstract: A porous optical fiber provided with air holes and a method for manufacturing the same are disclosed. The porous optical fiber includes a core having a first refractivity extended in a longitudinal direction, an external cladding layer having a second refractivity surrounding the core, and an internal cladding layer having a third refractivity formed between the core and the external cladding layer and provided with a plurality of air holes scattered therethrough.

Abstract: This invention relates to a method for forming a nano-imprinted photonic crystal waveguide, comprising the steps of: preparing an optical film on a substrate; preparing a template having a plurality of protrusions of less than 500 nm in length such that the protrusions are spaced a predetermined distance from each other; heating the film; causing the template to press against the heated film such that a portion of the film is deformed by the protrusions; separating the template from the film; and etching the film to remove a residual layer of the film to form a nano-imprinted photonic crystal waveguide.

Abstract: An apparatus for producing an optical fiber preform, having no seeds or bubbles at the central axis thereof and having no points at the central axis thereof where breaks may be initiated while drawing optical fiber therefrom, comprising bottom holding means 8 capable: of holding bottom end 9 of soot porous body 1 having centerline 10 consisting of mandrel 2; top holding means 11 capable of holding handle rod 3 of soot porous body 1; at least one pulling means 12 capable of holding and pulling mandrel 2 fitted in centerline 10 of soot porous body 1; at least one additional pulling means 13 capable of holding and pulling mandrel 2 when it is partly pulled out of centerline 10 of soot porous body 1 is provided. A mandrel pulling mechanism is also provided.

Abstract: An optical fiber coil of sub-micron diameter is shown to exhibit self-coupling between adjacent turns so as to form a three-dimensional optical resonator of relatively low loss and high Q. As long as the pitch of the coil and propagating wavelength remain on the same order (or less than) the fiber diameter, resonance may occur. Resonances can be induced by allowing adjacent turns of the coil to touch each other. Optical devices such as resonators and interferometers may then be formed from such “microcoils” that exhibit superior characteristics to conventional planar devices. A method of forming such a microfiber using indirect laser heating is also disclosed.

Abstract: A method for reducing the hydrogen sensitivity of an optical fiber is disclosed. The method includes a deuterium treatment step of exposing an optical fiber to a gas mixture including a deuterium, so that the optical fiber makes a contact with the deuterium, and a degassing step of degassing the optical fiber treated with the deuterium under a negative pressure condition.

Abstract: An optical waveguide circuit comprising a plurality of first cores (203) arranged at intervals widening as they are away from the branch point or the joining point of optical signal, a clad (205) filling at least these first cores, and second cores (204) provided between the first cores and the clad and formed in the gap between the first cores in the vicinity of the branch point or the joining point while covering the first cores at least partially. Refractive index of the second core is larger than that of the clad, the boundary between the second core and the clad is smooth and the film thickness of the second core formed in the gap between the first cores is decreased as the interval of the plurality of first cores widens.

Abstract: The present invention provides optical fiber coating systems and coated optical fibers. According to one embodiment of the invention, a coated optical fiber includes an optical fiber having a core and a cladding; and a primary coating encapsulating the optical fiber, the primary coating having a Young's modulus of about 5 MPa or less, the primary coating being the cured reaction product of a primary curable composition having a gel time less than about 1.4 seconds at a UV intensity of 3.4 mW/cm2.

Abstract: Methods of fabricating extra-mural absorption elements adapted for incorporation in an image-conducting optical fiber array include fabricating various constituent components to be included in an optical fiber bundle from one or more reducible-ion-containing glasses. Various components fabricated from a reducible-ion-containing glass are selectively exposed to a reducing atmosphere such that they are reduction-blackened prior to at least one heating and drawing step relative to the bundle into which they are to be fusedly incorporated. Such “pre-blackened” components function as extra-mural absorption media throughout the length of an image-conducting optical fiber array and alternatively include fiber claddings and substitutional and interstitial extra-mural absorption elements.

Abstract: A process and apparatus for elongating an optical fibre preform includes heating the preform so as to soften one region thereof; elongating the preform by submitting the preform to a traction; determining, during the step of elongating, the preform diameter in at least one measuring point along the preform; and controlling the step of elongating on the basis of the determined diameter. During the step of elongating, at least a geometrical parameter of the preform is measured, and the position of said diameter measuring point is controlled according to the measured geometrical parameter. Measuring at least a geometrical parameter of the preform may be accomplished by determining the profile of at least a portion of the softened region, e.g., an image of the neck region profile.

Abstract: A method to fabricate solid linear fiber arrays, multi-hole arrays and inverse multi-hole arrays (i.e. space-separated arrays). These arrays may be used for example as capillary arrays, photonic crystal fiber, tissues engineering scaffolds and templates, imaging guides, thermal photovoltaic device, and thermal electric devices. The number of fibers used to fabricate the structures is variable. Individual fibers are deposited into a fiber depository and made to bond together. The deposition may be performed in line with fiber production or may be performed after producing the fibers through fiber rewinding. The bonded linear fiber array may be removed from the fiber depositories.

Abstract: There is provided a polarization maintaining optical fiber coupler and a method of manufacturing this polarization maintaining optical fiber coupler in which manufacturing is simplified and excess loss is reduced. A polarization maintaining optical fiber coupler is provided in which, in at least one of the polarization maintaining optical fibers forming the fused and extended portion, the ratio of the [diameter of the core/the diameter of the cladding] or [the distance between the two stress applying portions/the diameter of the cladding] is greater than the ration of the [diameter of the core/the diameter of the cladding] or [the distance between the two stress applying portions/the diameter of the cladding in the portions of the polarization maintaining optical fibers that do not form the fused and extended portion]. In addition, in this polarization maintaining optical fiber coupler, in the fused and extended portion, the stress applying portions are enveloped by the cladding.

Abstract: A single free-beam region for coupling electromagnetic radiation in and out is provided in order in the case of an AWG coupler for spectrally separating electromagnetic radiation to achieve a more stable thermal characteristic and a space-saving layout.

Abstract: An optical waveguide is formed on a substrate and includes a curved ridge structure, a curved optical path, and a buffer layer. The curved ridge structure is formed on the substrate so as to have a curvature in a longitudinal direction of the curved ridge structure. The curved optical path is formed along the curved ridge structure. The buffer layer covers a side of the ridge structure and has a lower refractive index than a refractive index of the substrate.

Abstract: An optical fiber having a small increase in loss at a wavelength of approximately 1400 nm involved in a deuterium treatment is provided, and an evaluation method to decide whether an optical fiber is that having such a loss increase, and a fabrication method of an optical fiber having a small increase in such a loss are also provided. An optical fiber according to the present invention comprises a core composed of a silica glass doped with at least germanium and a cladding composed of a silica glass surrounding it. The optical fiber is exposed to an atmosphere containing hydrogen or deuterium to diffuse hydrogen molecules or deuterium molecules in the optical fiber, and after that, the outer periphery of the glass region of the optical fiber is etched to an outer diameter of 50 ?m, and then the electron spin density of PORs is 1×1013 spins/g or less when the glass region is measured by the electron-spin resonance method.

Abstract: Optical fiber having a glass portion; at least one protective coating of thermoplastic material having at least one thermoplastic elastomer; the thermoplastic material having the following characteristics: a modulus of elasticity value at +25° C. lower than 150 MPa, preferably at least 10 Mpa, more preferably higher than 20 Mpa, and a Vicat point higher than 85° C., preferably higher than 120° C., more preferably lower than 350° C. Preferably, the coating is a single protective coating directly positioned onto the glass portion.

Abstract: A Micro-Electro-Mechanical System (MEMS) and double-layer nozzle based high efficiency, lightweight, low cost, compact, portable fiber-optic connector cleaning apparatus useful for various fiber optic communications applications such as fiber optic cable plant maintenance. The double-layer nozzle design enables the delivery of compressed, filtered air and solvent to connector surfaces. A built-in MEMS pump sucks the air and solvent back to remove particles and contaminations without leaving residues and without scratching the connector surfaces. An interchangeable external needle allows the cleaner to quickly adapt to all kinds of fiber optic connectors. No disassembly is required. The connector cleaner is therefore both fast and effective at cleaning various male and female fiber optic connectors. The fiber optic connector cleaner with 3–5 cc solvent weighs less than half a pound and can be held and operated by one hand.

Abstract: The present invention provides a light-enhancing component and a fabrication method thereof by using the focused-ion-beam. In the present invention, the surface plasmon polariton structure is coated on the surface of the optical fiber so as to form the light-enhancing component. When the light passes through the optical fiber, the luminous flux transmitted through the aperture on the surface plasmon polariton is enhanced, and the light beam smaller than the diffraction limitation can be transmitted to the far-field, i.e. the nano-optic sword is formed. The light-enhancing component of the present invention can be used for the optical data storage, the optical microscopy, the biomedical detections and the lithography to perform the extra optical resolutions beyond the diffraction limitation.

Abstract: The invention relates to a method for manufacturing optical glasses and colored glasses with the aid of a fluid phase sintering process from a basic material encompassing at least SiO.sub.2 powder as well as additives for reducing the temperature of the fluid phase sintering and/or melting process encompassing the following steps: the starting materials are dissolved in any sequence in a fluid medium to produce a solution as far as is possible and a suspension to the extent that they are not dispersed in solution; a greenbody is produced from the dissolved and dispersed starting materials; the greenbody is dried the dried greenbody is fluid-phase sintered at temperatures below 1200° C., in particular in the temperature range from 600° C. to 1200° C.

Abstract: A method is provided for making ferrules for connecting optical fibers to other optical fibers or to an optical input device such as an optical chip. The method utilizes ceramic greensheets or silicon wafers. In one method, the greensheets are stacked and laminated and then fiber optic through openings are provided in the laminate for holding the fibers. The laminate is then sintered forming the ferrule.

Abstract: A method of joining a first optical fiber (110) to a second optical fiber (130) comprises the steps of: (i) providing a preform element (10) comprising material defining a primary elongate cavity (40); (ii) inserting the first optical fiber (110) into the primary cavity (40) to form a preform (125); and (iii) drawing the second optical fiber (130) from the preform (125); wherein, the second optical fiber (130) includes a core region comprising material that has been drawn from the first optical fiber (110).

Abstract: The present invention concerns a method of manufacturing a graded index plastic optical fiber having an index that varies continuously between the center and the periphery of the fiber, from at least one polymer P and at least one reactive diluent D1 to allow the refractive index of said fiber to be varied.

Abstract: A system and method for fabricating structures in an optical substrate. An optical element produces first and second write beams that intersect at a first intersection location at the optical substrate. The first intersection location includes a fringe pattern produced by the first and second write beams. The optical element also produces first and second reference beams that intersect and are recombined at a second intersection location in substantially the same plane as the first intersection location. A controller then controls relative positioning between the optical substrate and the fringe pattern based on a signal derived from the recombined first and second reference beams.

Abstract: This invention provides a process for producing a three-dimensional polyimide optical waveguide, which comprises: (I) irradiating a polyamic acid film with a laser beam while converging the laser beam at an inside portion of the film and relatively moving the light convergence point, the polyamic acid film containing: (a) a polyamic acid obtained from a tetracarboxylic dianhydride and a diamine; and (b) per 100 parts of the polyamic acid, from 0.5 part by weight to less than 10 parts by weight of a specific 1,4-dihydropyridine derivative represented by formula (I): and then, (II) heating the polyamic acid film to imidize the polyamic acid, thereby obtaining an optical waveguide having a continuous core region where the refraction index has been changed, in the thus formed polyimide film.

Abstract: An optical fiber for optical amplification, characterized in that a full width at half maximum of gain spectrum is 45 nm or more; and a maximum value of power conversion efficiency is 80% or more. A method for producing a rare earth element-doped glass for use in manufacturing the optical fiber, which comprises a deposition step of depositing fine silica glass particles and a co-dopant (a) to prepare an aggregate of fine silica glass particles doped with the co-dopant (a); and a immersion step of immersing the aggregate of fine silica glass particles prepared in the deposition step in a solution containing the rare earth element and the co-dopant (b) to thereby dope the aggregate of fine silica glass particles with the rare earth element component and the co-dopant (b).

Abstract: An apodized fiber Bragg grating, and a phase mask, method and system for making such a grating are disclosed. The refractive index profile of the grating has a periodic apodization phase component which is designed so that the grating fringes reflecting light in a spectral region of interest are apodized, by generating spurious reflection features outside of this spectral region of interest. Apodization is therefore provided through a phase variation of the grating as opposed to an amplitude variation. The phase component is added to the profile of the phase mask grating corrugations to obtain the phase-apodized grating.

Abstract: The present invention provides methods for forming convex and concave elements on the ends of supporting members. A convex element may be formed by forming a droplet on the end of the supporting member, then curing the droplet. The size of the droplet may be controlled using evaporation of a solvent from the droplet. In another aspect of the invention, an optical element may be formed by forming a droplet on the end of the supporting member, contacting the droplet with a mold, and curing the droplet, thereby forming an element with a curvature opposite that of the mold. When the supporting member is an optical fiber, the elements formed by the methods of the present invention are useful as lenses and mirrors in micro-optic devices.

Abstract: An optical waveguide is formed on a substrate and includes a curved ridge structure, a curved optical path, and a buffer layer. The curved ridge structure is formed on the substrate so as to have a curvature in a longitudinal direction of the curved ridge structure. The curved optical path is formed along the curved ridge structure. The buffer layer covers a side of the ridge structure and has a lower refractive index than a refractive index of the substrate.

Abstract: A fiber optic article can comprise a core, an inner region disposed about the core and a cladding disposed about the inner region. The index of refraction of the cladding can be less than that of the inner region, and the index of refraction of the inner region can be less than that of the core. The fiber can include a second cladding disposed about the cladding, where the second cladding has an index of refraction that is less than the index of refraction of the cladding. The inner region can have a non circular outer perimeter that includes at least one inwardly oriented section. The article can be elongate along a longitudinal axis and can include at least one longitudinally extending region, such as a stress inducing region, for providing birefringence and the inwardly oriented region can face the longitudinally extending region. The fiber optic article can include active material for providing light responsive to the article receiving pump light, such as, for example, one or more rare earths.

Abstract: Silicon-oxycarbide optical waveguides and thermooptic devices include a substrate and a first cladding layer having a first refractive index positioned over a substrate. A first core layer comprising silicon, oxygen, and carbon and having a core refractive index is formed on the first cladding layer by chemical vapor deposition using at least two precursors: one inorganic silicon precursor gas and at least one second precursor gas comprising carbon and oxygen. Alternatively, at least three precursors can be used: one inorganic silicon precursor gas, a second precursor comprising carbon, and a third precursor comprising oxygen. The core layer is lithographically patterned to define waveguide elements. A second cladding layer having a second cladding refractive index is formed to surround the optical core waveguiding element of the first core layer.

Abstract: A graded-index multimode fiber includes a core containing fluorine and a cladding which is provided at an outer periphery of the core, and the fiber has a refractive index profile which satisfies the following Formula (1): n ? ( r ) = { n 1 ? [ 1 - 2 ? ? ? ? ? ( r a ) ? ] 1 / 2 ( O ? r ? a ) n 1 ? ( 1 - 2 ? ? ? ) 1 / 2 ( r > a ) ( 1 ) where n(r) is a refractive index of the optical fiber at a distance “r” from the center of the core, n1 is a refractive index at the center of the core, ? is a relative refractive index difference of the center of the core with respect to the cladding, “a” is a core radius, and ? is a refractive index profile exponential parameter.

Abstract: In the known method for producing an optical fiber, a coaxial arrangement comprising a core rod and an outer jacket tube is elongated, the coaxial arrangement being supplied in a vertical orientation to a heating zone and being softened therein zonewise, starting with the lower end thereof, and the optical fiber being withdraw downwards from the softened portion, whereby an annular gap existing between core rod and jacket tube is collapsed. Starting therefrom, in order to provided a method which makes it possible to produce optical fibers with a minimum curl and at low costs, the invention suggests that a quartz glass cylinder treated mechanically to its final dimension and having an outer diameter of at least 100 mm should be used as the jacket tube. An optical fiber obtained according to the method is characterized in that without the action of external forces it assumes a radius of curvature of at least 6 mm.

Abstract: An object of the present invention is to provide an optical fiber manufacturing method and an optical fiber in which an increase in the transmission loss is suppressed by preventing hydroxyl group from entering near the core portion. This invention provides a method for manufacturing an optical fiber 10 including forming a glass pipe 16 by applying a ring portion 15 on the inner face of a starting pipe 14 as a starting material, inserting a glass rod 13 that becomes a central core portion 11 and a depressed portion 12 into the inside of the glass pipe 16, integrating the glass pipe 16 and the glass rod 13 by collapse to form a glass body 17, forming a preform 10a by providing a jacket portion 18 outside the glass body 17, and drawing the preform 10a, wherein the thickness of the starting pipe 14 is set in a range from 4 mm to 8 mm.

Abstract: The end face of an optical fiber 11 is polished at an angle to alter the cross-sectional dimensions of a light beam exiting the fiber through that end face to alter the cross-sectional circularity of the light beam after it has exited the fiber as compared to its cross-sectional circularity when it is in the fiber. For example, to increase the circularity of an exiting light beam, the angled fiber end face can be aligned such that the major axis of the sloping fiber end face is aligned with the major cross-sectional axis of the light beam in the fiber (i.e. perpendicular to the minor cross-sectional axis of the light beam in the fiber). This has the effect of reducing the length of the major cross-sectional axis of the light beam once it has exited the fiber.

Abstract: A method for manufacturing an optical waveguide component with several layers stacked on a silicon substrate. The layers include a buffer layer, a first substrate, a guiding layer on the buffer layer and including an optical waveguide, and an outer layer as protection against external stresses. The layers are made from an organic-inorganic hybrid using a sol-gel process. An additional layer is disposed on the guiding layer so that a symmetrical structure is produced that has the same refractive index around the waveguide in the guiding layer.

Abstract: A photonic crystal includes a phosphor matrix and a plurality of defect regions. The phosphor matrix defines a plurality of substantially spherical voids arranged in a triangular lattice arrangement. The phosphor matrix has a first index of refraction. The plurality of defect regions is distributed in a subset of the spherical voids. Each defect region has a second index of refraction that is different from the first index of refraction.

Abstract: An optical waveguide comprising cladding 1 and core segment 20 buried in cladding 1 and serving as a waveguide, wherein a combination of glass material constituting the core segment 20 and another glass material constituting the cladding 1 is so selected that an absolute value of difference in coefficient of thermal expansion between these materials (?1-?2) is within a range of 0 and 9×10?7° C., where ?1 denotes a coefficient of thermal expansion of the former material and ?2 denotes that of the latter material.

Abstract: A method of producing a short-pass fiber by drawing a preform for a depressed cladding fiber at a predetermined drawing ratio. The preform has a core of refractive index n0, a depressed cladding surrounding the core and having a refractive index n1, and a secondary cladding surrounding the depressed cladding and having a refractive index n2. The core has a core cross-section and the depressed cladding has a depressed cladding cross-section that is larger than the core cross-section. The drawing ratio is determined based on the parameters of the preform measured along the axis of the preform and based on a desired minimum fundamental mode cutoff wavelength ?m. The final core cross-section defines a fundamental mode cutoff wavelength ?c such that ?c??m along the axis. Then the preform is pulled by the thus-determined drawing ratio to produce the short-pass fiber. In some embodiments a test section of the fiber is pulled first before pulling the short pass fiber.

Abstract: An optical fiber structure having a holey fiber arranged in a holey outer support structure made up of holey tubes encased in a thin walled outer jacket. The holey fiber may have a solid core surrounded by a holey cladding having a plurality of rings of holes. With the invention it is possible to produce robust, coated and jacketed fibers with microstructured core features of micrometer size relatively easily using existing fiber fabrication technology. This improvement is a result of the outer holey structure which reduces the thermal mass of the supporting structure and makes it possible to reliably and controllably retain small hole features during the fiber fabrication process.

Abstract: Machining of crystalline lithium niobate is carried out utilizing a laser having a beam with a wavelength near the absorption edge of lithium niobate. The laser beam is provided in pulses of short duration and at a repetition rate selected to ablate the surface of the lithium niobate without damaging the bulk material. Translation of the laser beam and the substrate with respect to each other can be carried out to define a trench of a desired geometry in the lithium niobate.

Abstract: A method of forming a field emission device and the resulting device including emitters formed of fiber segments. Tips are formed on the fiber segments that have a radius substantially small by exposing the tips to a reactive liquid for a duration of time The tips are coated with a low work function conducting material to form emitters.

Abstract: When an optical waveguide is formed by focused femtosecond laser pulses in a pure silica glass to induce a refractive index increase region, a pulse width of femtosecond laser pulses are changed, a peak power of femtosecond laser pulses at the focal point is changed, or both the pulse width and the peak power are changed simultaneously. Under conditions where a pulse width of the femtosecond laser pulses is in a range of 210 to 420 fs and a peak power at the focal point is not greater than 8.7×1011 W/cm2, an optical waveguide having a mode field of 10 to 14 ?m such that an aspect ratio is 1 (one) can be obtained. By doing this, it is possible to control a mode field diameter of an optical waveguide and an aspect ratio of the mode field diameter.

Abstract: An optical fiber characterized by a cutoff wavelength of 1310 nm or less, a transmission loss of 0.40 dB/km or less at the wavelength of 1385 nm before hydrogen ageing, a transmission loss of 0.40 dB/km or less in the wavelength range of 1310 nm to 1625 nm after hydrogen ageing, and an electron spin density of the Non-Bridging Oxygen Hole Center of 1×1013spins/g or less measured by the electron spin resonance method after the diameter of the optical fiber is made to be about 50 ?m by etching in diluted hydrofluoric acid, that having high reliability of hydrogen-proof characteristic suitable for WDM transmission in 1310 nm to 1625 nm and the method of evaluating the optical fiber are offered.

Abstract: Disclosed is a substantially transparent glass-ceramic ceramic, and a method for making a glass-ceramic, exhibiting an aluminogallate spinel crystal phase and having a glass-ceramic composition that lies within the SiO2—Al2O3—ZnO—K2O—Ga2O3—Na2O system and particularly consisting essentially, in weight percent on an oxide basis, of 25-50% SiO2, 15-45% ZnO, 0-26% Al2O3, 0-25% K2O, 0-10% Na2O, 0-32% Ga2O3, a K2O+Na2O amount of greater than 10%, a Al2O3+Ga2O3 of greater than 10%, the glass ceramic microstructure containing a crystal phase comprising at least 15%, by weight, of hexagonal ZnO crystals. Another aspect disclosed is optical element selected from the group consisting of an optical fiber, a gain or laser medium, and an amplifier component, a saturable absorber, with the element comprising a transparent glass-ceramic of the same composition and containing a crystallinity of at least about 15% by weight of hexagonal ZnO crystals.

Abstract: Disclosed is a method of making a photonic crystal optical fiber preform by stacking and bonding individual glass disks. In one embodiment, each glass disk has a pattern of voids formed therethrough, and the pattern for each disk is the same. In another embodiment, glass blanks are formed without voids and stacked with disks having voids wherein an optical fiber preform is formed having channels closed at both ends by glass having no channels. Also disclosed is an optical fiber having channels closed at both ends by glass without channels.

Abstract: A method of fabricating an optical fiber preform using a modified chemical vapor deposition method and a nonlinear optical fiber fabricated using the method. The method comprises the steps of: forming a cladding layer and a core layer in a quartz glass tube; partially sintering the core layer; partially shrinking both ends of the quartz glass tube, in which the cladding layer and the core layer partially sintered are formed; and doping a sintered portion of the core layer with an impurity component, so that the optical fiber preform fabricated has a predetermined function. The nonlinear optical fiber being fabricated by a process comprising the steps of: forming the cladding layer and the core layer in a quartz glass tube; partially sintering the core layer; partially collapsing both ends of the quartz glass tube; and doping a sintered portion of the core layer with a predetermined impurity component.

Abstract: An optical fiber with microstructures comprises a plurality of capillary tubes disposed around a central rod and including a self-cleaning layer including molecules able to react with hydroxyl molecules to produce volatile gaseous substances.

Abstract: The method for making the fiber optic Fabry-Perot sensor includes securing an optical fiber to a substrate, and forming at least one gap in the optical fiber after the optical fiber is secured to the substrate to define at least one pair of self-aligned opposing spaced apart optical fiber end faces for the Fabry-Perot sensor. Preferably, an adhesive directly secures the at least one pair of optical fiber portions to the substrate. The opposing spaced apart optical fiber end faces are self-aligned because the pair of optical fiber end portions are formed from a single fiber which has been directly secured to the substrate. Also, each of the self-aligned spaced apart optical fiber end faces may be substantially rounded due to an electrical discharge used to form the gap. This results in integral lenses being formed as the end faces of the fiber portions.

Abstract: In a method of producing a photonic crystal fibre, a preform (300) that includes holes is formed and the preform (300) is drawn into a fibre. The method includes the step of applying a pressure differential to certain of the holes to control changes in the fibre structure during the draw.