Abstract: The present invention relates generally to optical waveguides, and more particularly to optical fibers suitable for use with high optical energies, and to devices using them. One aspect of the invention is an optical fiber having a cross-sectional profile comprising a base glass material; a first ring of first low refractive index glass features disposed in the base glass material; and a second ring of second low refractive index glass features disposed in the base glass material outside of and substantially concentric with the first ring, wherein the optical fiber has a loss of less than about 0.7 dB/m for the fundamental mode and a loss greater than about 10 dB/m for all other modes in a coiled configuration having a coil diameter in the range of about 20 cm to about 200 cm.

Abstract: Various embodiments of optical fiber designs and fabrication processes for ultra small core fibers (USCF) are disclosed. In some embodiments, the USCF includes a core that is at least partially surrounded by a region comprising first features. The USCF further includes a second region at least partially surrounding the first region. The second region includes second features. In an embodiment, the first features are smaller than the second features, and the second features have a filling fraction greater than about 90 percent. The first features and/or the second features may include air holes. Embodiments of the USCF may provide dispersion tailoring. Embodiments of the USCF may be used with nonlinear optical devices configured to provide, for example, a frequency comb or a supercontinuum.

Abstract: An optical fiber includes a core portion that confines light therein and guides the light therethrough and a cladding portion that is formed around an outer circumference of the core portion. The cladding portion contains a hole which is formed at a position a distance away from the core portion such that the hole does not substantially affect an effective core area or a chromatic dispersion characteristic of the optical fiber. The hole decreases a microbending loss of the optical fiber.

Abstract: Systems and methods for coupling light into a transparent sheet. The systems include a light source and a light-diffusing optical fiber optically coupled to the light source. The light-diffusing optical fiber has a core, a cladding and a length, with at least a portion of the core comprising randomly arranged voids configured to provide substantially continuous light emission from the core and out of the cladding along at least a portion of the length, and into the transparent sheet.

Abstract: The invention aims to provide a holey fiber that can release leak light propagating through the clad at a desired location, and a laser device using the holey fiber. A holey fiber includes: one end and the other end; a core; an inner clad coating the core; a hole layer having a large number of holes formed therein and coating the inner clad; and an outer clad coating the hole layer. In this holey fiber, a collapse region is formed, and the holes in the collapse region are squashed by a predetermined length in the length direction of the fiber.

Abstract: The specification describes an optical fiber color coding scheme that uses two colors, where each of the two colors constitutes one half of the surface of the optical fiber coating. If a longitudinal portion of the coating is considered a hollow cylinder, then each of the two colors is a hollow hemi-cylinder. To ensure that each of the two colors is always plainly visible to an installer, the two colors are formed with a twist. Using two colors for coding substantially increases the number of available unique color codes. Coloring the entire coating reduces the chances of error in identifying the optical fibers.

Abstract: The present invention relates to a hybrid photonic crystal fiber, into the core of which a functional material is injected. The hybrid photonic crystal fiber of the present invention comprises: a central hole having a diameter of 4 to 15 ?m extending in the longitudinal direction; an inner cladding also formed in the longitudinal direction outside the central hole, having a hexagonal arrangement of air holes, each of which has a diameter of 2 to 5 ?m and a lattice constant of 4.5 to 7 ?m; an annular outer cladding surrounding the outer surface of the inner cladding; and a core formed by filling a functional material in some of the air holes including the central hole. According to the present invention, changes in the state, i.e. the liquid, liquid-crystal, or biofluid states, of the functional material that fills the core that has a variety of shapes may enable the modulation of light intensity, wavelength, phase, and polarization, and thus enable various photonic networks to be produced.

Abstract: Optical fiber waveguides and related approaches are implemented to facilitate communication. As may be implemented in accordance with one or more embodiments, a waveguide has a substrate including a lattice structure having a plurality of lattice regions with a dielectric constant that is different than that of the substrate, a defect in the lattice, and one or more deviations from the lattice. The defect acts with trapped transverse modes (e.g., magnetic and/or electric modes) and facilitates wave propagation along a longitudinal direction while confining the wave transversely. The deviation(s) from the lattice produces additional modes and/or coupling effects.

Abstract: In general, in one aspect, the disclosure features a system that includes a flexible waveguide having a hollow core extending along a waveguide axis and a region surrounding the core, the region being configured to guide radiation from the CO2 laser along the waveguide axis from an input end to an output end of the waveguide. The system also includes a handpiece attached to the waveguide, wherein the handpiece allows an operator to control the orientation of the output end to direct the radiation to a target location of a patient and the handpiece includes a tip extending past the output end that provides a minimum standoff distance between the output end and the target location.

Abstract: A microstructured optical fiber exhibiting enhanced circularity of the guided light mode is provided. The microstructured optical fiber includes a light-guiding core and a primary cladding surrounding the core wherein the primary cladding has a plurality of holes arranged in hexagonal unit cells defining an Archimedean-like lattice. Preferably, the core is defined by a break in a center of the Archimedean-like lattice, the break being characterised by an absence of at least one of the unit cells. Also preferably, each of the unit cells has seven holes arranged in a centred hexagon. A method of making the microstructured optical fiber is also provided. The method includes fabricating a fiber preform by stacking a plurality of canes around a rod, each cane having a number of holes arranged in a unit cell defining an Archimedean-like lattice, and drawing said fiber preform into the microstructured optical fiber.

Abstract: An optical transmission system includes an optical transmitting unit that outputs at least one optical signal having a wavelength included in an operation wavelength band and a holey fiber that is connected to the optical transmitting unit. The holey fiber includes a core and a cladding formed around the core. The cladding includes a plurality of holes formed around the core in a triangular lattice shape. The holey fiber transmits the optical signal in a single mode. A bending loss of the holey fiber is equal to or less than 5 dB/m at a wavelength within the operation wavelength band when the holey fiber is wound at a diameter of 20 millimeters.

Abstract: A polarization-maintaining (PM) optical fiber has a pure silica core surrounded by a cladding having a region with randomly arranged voids. Stress members are arranged in the cladding on opposite sides of and in line with the core, and impart birefringence to the PM optical fiber. The PM optical fiber is resistant to aging effects and has a broad single-mode spectral range of 400 nm to 1,600 nm.

Abstract: Light-coupling systems and methods that employ light-diffusing optical fiber are disclosed. The systems include a light source and a light-diffusing optical fiber optically coupled thereto. The light-diffusing optical fiber has a core, a cladding and a length. At least a portion of the core comprises randomly arranged voids configured to provide substantially spatially continuous light emission from the core and out of the cladding along at least a portion of the length. A portion of the light-diffusing optical is embedded in an index-matching layer disposed adjacent a lower surface of a transparent sheet. Light emitted by the light-diffusing optical fiber is trapped within the transparent sheet and index-matching layer by total internal reflection and is scattered out of the upper surface of the transparent sheet by at least one scattering feature thereon.

Abstract: The invention aims to provide an optical fiber in which light that is input to the clad is easily released to the outside of the clad, and a laser device using the optical fiber. An optical fiber (50) includes a core (51), and a clad (52) coating the core (51). The clad (52) includes a refractive-index varying region (56) in which the refractive index increases in the direction from the inner circumferential side toward the outer circumferential side. In this structure, even when light is input to the clad (52), the light that has reached the refractive-index varying region (56) of the clad (52) is refracted and propagates from the inner circumferential side toward the outer circumferential side of the clad (52). Accordingly, light that is input to the clad (52) is easily released to the outside of the clad (52).

Abstract: Various embodiments described include optical fiber designs and fabrication processes for ultra high numerical aperture optical fibers (UHNAF) having a numerical aperture (NA) of about 1. Various embodiments of UHNAF may have an NA greater than about 0.7, greater than about 0.8, greater than about 0.9, or greater than about 0.95. Embodiments of UHNAF may have a small core diameter and may have low transmission loss. Embodiments of UHNAF having a sufficiently small core diameter provide single mode operation. Some embodiments have a low V number, for example, less than 2.4 and large dispersion. Some embodiments of UHNAF have extremely large negative dispersion, for example, less than about ?300 ps/nm/km in some embodiments. Systems and apparatus using UHNAF are also disclosed.

Abstract: The present invention relates to a light source apparatus. The light source apparatus has an MOPA configuration and comprises a seed light source, a pulse generator, an intermediate optical amplifier, a final stage optical amplifier, a delivery optical fiber, and a light output terminal. The delivery optical fiber is a PBG fiber having a photonic bandgap (PBG) structure in a core-surrounding portion located around the core. Light with a wavelength in a high loss band of the PBG fiber is inputted into the PBG fiber.

Abstract: A true time delay system for optical signals includes a hollow core optical waveguide, a droplet of reflective liquid metal disposed in the hollow core, and an actuator coupled to a first end of the waveguide to move the droplet longitudinally within the hollow core. In one example, the waveguide is a hollow core photonic bandgap fiber. In one example, the actuator is a pressure actuator that introduces or removes gas into the core. Light enters the optical fiber, is transmitted through the fiber toward the reflective surface of the droplet, and is reflected back through the fiber and exits at the same end of the photonic bandgap optical fiber that it entered. The fiber optic device can provide a continuously-variable optical path length of over 3.6 meters (corresponding to a continuously-variable true-time delay of over 12 ns, or 120 periods at a 10 GHz modulation frequency), with negligible wavelength dependence across the C and L bands.

Abstract: In one embodiment, an waveguide includes a primary core configured to guide electromagnetic waves having relatively long wavelengths, a unit cell having a core configured to guide electromagnetic waves having relatively short wavelengths, the relatively long wavelengths being at least twice as long as the relatively short wavelengths, and a cladding material that surrounds the primary core and the unit cell.

Abstract: A flexible optical interconnect and method of forming the interconnect is disclosed. The optical interconnect includes a waveguide base formed from a flexible dielectric material. A three-sided channel is formed in the flexible material. Each side of the channel is coated with a reflective metallic coating. A cover piece is formed from the flexible material and coated with a reflective metallic coating on an underside. The cover piece is coupled to the waveguide base to form a flexible optical bus having at least one hollow metallized waveguide. The hollow metallized waveguide is configured to carry an optical signal. A transverse slot is formed in the cover piece and the waveguide base to form an aperture bisecting the hollow metallized waveguide to enable the optical signal to be detected and/or redirected.

Abstract: The present invention relates to an optical fiber having a structure to enable both prevention of resin coating combustion due to leaked light, and low-loss light transmission. The optical fiber comprises a core region, and a cladding region. The cladding region is constituted by an optical cladding which affects the transmission characteristics of light propagating in the core region, and a physical cladding which does not affect the transmission characteristics of light propagating in the core region. Particularly, a leakage reduction portion is provided in the physical cladding so as to surround an outer periphery of the core region through the optical cladding. The leakage reduction portion functions to suppress propagation of the leaked light propagating from the core region toward outside the cladding region.

Abstract: A guiding element suitable for integrated optics and transmission in the visible wavelength region includes a plurality of sub-wavelength sized regions in two parallel periodic arrangements embedded within a waveguide layer located on a planar substrate. The dielectric constant of each regions may be the same but different from that of the substrate, the waveguide layer, and the cladding. The periodicity, dimensions and shape of the regions of the periodic arrangement are selected to achieve the desired transmission and guiding of the incident radiation spectrum (e.g., parallel to the two periodic arrangements). A transparent layer with a dielectric constant between the dielectric constant of the periodic arrangement and the dielectric constant of the substrate/cladding provides confinement normal to the substrate.

Abstract: An optical fiber has an incident end on which light is incident, an emitting end from which the light is emitted, and an aperture provided in a core located at or near the emitting end. The aperture is formed by irradiating the core with an ultrashort pulsed laser beam having pulse widths of 10?15 seconds to 10?11 seconds.

Abstract: There is provided an optical waveguide comprising an optical core having transverse sides, the optical core extending along a curved path; an optical cladding on the transverse sides of the optical core, wherein the distribution of the optical cladding on the transverse sides of the optical core is asymmetric about the centre of the core.

Abstract: An apparatus for inspecting a specimen, such as a semiconductor wafer, is provided. The apparatus comprises a laser energy source, such as a deep ultraviolet (DUV) energy source and an optical fiber arrangement. The optical fiber arrangement comprises a core surrounded by a plurality of optical fibers structures used to frequency broaden energy received from the laser energy source into frequency broadened radiation. The frequency broadened radiation is employed as an illumination source for inspecting the specimen. In one aspect, the apparatus comprises a central core and a plurality of structures generally surrounding the central core, the plurality of fibers surround a hollow core fiber filled with a gas at high pressure, a tapered photonic fiber, and/or a spider web photonic crystalline fiber, configured to receive light energy and produce frequency broadened radiation for inspecting the specimen.

Abstract: A photovoltaic (PV) system includes a fiber optical waveguide comprising an active core that hosts material configured to absorb and emit light, a cladding layer surrounding the active core, the cladding layer being configured to allow ambient light to pass through the cladding layer, and an exit port located proximate an end of the waveguide. The PV system further comprises one or more solar cells disposed at the exit port of the waveguide. The waveguide is configured to guide light to the one or more solar cells. Another photovoltaic (PV) system includes a waveguide comprising an active cladding layer hosting material configured to absorb and emit light, and a core layer configured to confine light emitted by the active cladding layer. The PV system further includes one or more solar cells disposed proximate the waveguide. The core layer is configured to guide light to the one or more solar cells.

Abstract: Light diffusing optical fibers and methods for producing light diffusing optical fibers are disclosed. In one embodiment, a light diffusing optical fiber includes a core portion formed from silica glass and comprising a plurality of helical void randomly distributed in the core portion of the optical fiber and wrapped around the long axis of the optical fiber. A pitch of the helical voids may vary along the axial length of the light diffusing optical fiber in order to achieve the desired illumination along the length of the optical fiber. A cladding may surround the core portion. Light guided by the core portion is scattered by the helical voids radially outward, through the cladding, such that the light diffusing optical fiber emits light with a predetermined intensity over an axial length of the light diffusing optical fiber, the light diffusing optical fiber having a scattering induced attenuation loss greater than about 0.2 dB/m at a wavelength of 550 nm.

Abstract: The present invention is a method and an apparatus for dynamic manipulation and dispersion in photonic crystal devices. In one embodiment, a photonic crystal structure comprises a substrate having a plurality of apertures formed therethrough, a waveguide formed by “removing” a row of apertures, and a plurality of pairs of lateral electrical contacts, the lateral electrical contact pairs extending along the length of the waveguide in a spaced-apart manner. The lateral electrical contact pairs facilitate local manipulation of the photonic crystal structure's refractive index. Thus, optical signals of different wavelengths that propagate through the photonic crystal structure can be dynamically manipulated.

Abstract: A method of coupling a spliceable optical fiber includes (A) providing the spliceable optical fiber, the spliceable optical fiber including (a) a core region; and (b) a microstructured cladding region. The cladding region surrounds the core region and includes (b1) an inner cladding region having a refractive index formed by inner cladding features arranged in an inner cladding background material with a refractive index n1, the inner cladding features including thermally collapsible holes or voids, and (b2) an outer cladding region with an outer cladding background material with a refractive index n2, the spliceable optical fiber having at least one end. (B) Collapsing the thermally collapsible holes or voids by heating the at least one end of the spliceable optical fiber thereby increasing the refractive index of the inner cladding providing an expanded core. And, (C) coupling the collapsed spliceable optical fiber end to the optical component.

Abstract: Various embodiments include photonic bandgap fibers (PBGF). Some PBGF embodiments have a hollow core (HC) and may have a square lattice (SQL). In various embodiments, SQL PBGF can have a cladding region including 2-10 layers of air-holes. In various embodiments, an HC SQL PBGF can be configured to provide a relative wavelength transmission window ??/?c larger than about 0.35 and a minimum transmission loss in a range from about 70 dB/km to about 0.1 dB/km. In some embodiments, the HC SQL PBGF can be a polarization maintaining fiber. Methods of fabricating PBGF are also disclosed along with some examples of fabricated fibers. Various applications of PBGF are also described.

Abstract: A method and apparatus for making a substantially void-free preform for a microstructured optical fiber using a one-step process is provided. A preform is prepared from specialty glasses using a direct extrusion method. A die for use with the direct extrusion method is also provided, and a method for drawing the preform into a HC-PBG fiber for use in transmitting infra-red wavelength light is also provided. The preform comprises an outer jacket made of solid glass, a cladding having a plurality of air holes arranged in a desired pattern within the jacket, and a core which is hollow.

Abstract: A manufacturing method of a photonic band gap fiber which includes measuring a hole diameter d0 and a distance-between-holes ?0 in a preliminary experiment capillary body by first drawing a preliminary experiment preform, calculating a confinement loss to a normalized wavelength ?/? being a wavelength ? normalized by an optional distance-between-holes ? using a ratio d0/?0 and the optional distance-between-holes ? as design parameters, setting a distance-between-holes by calculating the set distance-between-holes ?1 to a desired transmission wavelength ?1 of a photonic band gap fiber to be manufactured using a value of the normalized wavelength ?/? in which the confinement loss becomes about a minimum value, and second drawing a preform for a photonic band gap fiber by using the same members as those of the preliminary experiment preform and by setting a distance-between-holes to the set distance-between-holes ?1, in a drawing temperature condition used for the first drawing.

Abstract: A hybrid waveguide device includes a hollow core fiber having a core formed by a combination of solid material and gases. The hybrid nature of the core allows the hybrid device to transport a high energy high power laser beam having an ultra-short pulse width without damage to the hybrid device due to a higher tolerance of irradiance than single-matter cores. A waveguide device having a core with gases in addition to solid matter is characterized by a lower nonlinear refractive index coefficient (n2), lower numerical aperture, larger delivering laser beam size, and higher ionization potential of the gases. As a result, the hybrid waveguide fiber can transport ultra-short laser pulses having ablative energy levels and power levels, for example from a laser generating subassembly to a laser material-modification subassembly.

Abstract: Methods and apparatus for generating ultrashort optical pulses. Polarized pulses of a near-infrared source are launched substantially along a principle axis of a birefringent photonic crystal fiber characterized by normal dispersion at all wavelengths of transmission of the photonic crystal fiber. Supercontinuum pulses are generated from the photonic crystal fiber and compressed to form compressed pulses. Highly polarized supercontinuum pulses provide for transform-limited compressed pulse durations.

Abstract: A random array of holes is created in an optical fiber by gas generated during fiber drawing. The gas forms bubbles which are drawn into long, microscopic holes. The gas is created by a gas generating material such as silicon nitride. Silicon nitride oxidizes to produce nitrogen oxides when heated. The gas generating material can alternatively be silicon carbide or other nitrides or carbides. The random holes can provide cladding for optical confinement when located around a fiber core. The random holes can also be present in the fiber core. The fibers can be made of silica. The present random hole fibers are particularly useful as pressure sensors since they experience a large wavelength dependant increase in optical loss when pressure or force is applied.

Abstract: An embodiment of an apparatus includes an optical fiber for which a complete orthogonal basis of propagating modes at an optical telecommunication frequency includes ones of the propagating modes with different angular momenta. The optical fiber has a tubular optical core and an outer optical cladding in contact with and surrounding the tubular optical core. The tubular optical core has a larger refractive index than the optical cladding. The tubular optical core is configured such that those of the propagating modes whose angular momenta have the lowest magnitude for the propagating modes have substantially the same radial intensity profile.

Abstract: All solid photonic bandgap optical fiber comprising a core region and a cladding region is disclosed. The cladding region surrounding the core region includes a background optical material having a first refractive index and elements arranged in a two-dimensional periodic structure. In one embodiment, each of the elements comprises a center part and peripheral part having a higher refractive than the central part. In other embodiments, each element comprises a plurality of rods having a higher refractive index higher than the fist, the rods of each element arranged in a circle or polygon. Light transmission apparatus and methods of using the fiber are also disclosed.

Abstract: An apparatus includes an optical fiber having a plurality of optical cores therein. Each optical core is located lateral in the optical fiber to the remaining one or more optical cores and is able to support a number of propagating optical modes at telecommunications wavelengths. Each number is less than seventy.

Abstract: An optical transmission body includes a substrate having a through hole penetrating therethrough in a thickness direction thereof; a cladding member at least a part of which is positioned to be filled in the through hole, and which has an optical waveguide hole which is positioned inside the through hole and penetrates through the cladding member in a thickness direction thereof and a guide hole portion which is positioned away from the optical waveguide hole and is concave in the thickness direction; and a core member disposed inside the optical waveguide hole.

Abstract: A variable optical attenuator device is described that comprises a first optical input, a first optical output, a first optical path between the first optical input and the first optical output, and means for moving a shutter across said first optical path. A hollow core waveguide is provided to substantially guide light along the first optical path of the device. The device may also be used to provide an analogue beam splitting or switch function in telecommunication systems and the like.

Abstract: Various embodiments include photonic bandgap fibers (PBGF). Some PBGF embodiments have a hollow core (HC) and may have a square lattice (SQL). In various embodiments, SQL PBGF can have a cladding region including 2-10 layers of air-holes. In various embodiments, an HC SQL PBGF can be configured to provide a relative wavelength transmission window ??/?c larger than about 0.35 and a minimum transmission loss in a range from about 70 dB/km to about 0.1 dB/km. In some embodiments, the HC SQL PBGF can be a polarization maintaining fiber. Methods of fabricating PBGF are also disclosed along with some examples of fabricated fibers. Various applications of PBGF are also described.

Abstract: An optical fiber that has no bubbles in the ultraviolet ray curable resin filled inside the air holes to seal the end parts thereof, an end part processing method of the optical fiber, and an end part processing apparatus of the optical fiber, are provided. In an end part processing method of an optical fiber that is comprised of a core and a cladding formed around the core, the cladding having a refraction index lower than that of the core and has a plurality of air holes formed therein along the axis of the core, wherein the end part process of the optical fiber is to form sealed portions on the ends of the air holes by sealing them with ultraviolet ray curable resin, the method is characterized in that the sealed portion is formed by heating the end of the optical fiber.

Abstract: Various embodiments of optical fiber designs and fabrication processes for ultra small core fibers (USCF) are disclosed. In some embodiments, the USCF includes a core that is at least partially surrounded by a region comprising first features. The USCF further includes a second region at least partially surrounding the first region. The second region includes second features. In an embodiment, the first features are smaller than the second features, and the second features have a filling fraction greater than about 90 percent. The first features and/or the second features may include air holes. Embodiments of the USCF may provide dispersion tailoring. Embodiments of the USCF may be used with nonlinear optical devices configured to provide, for example, a frequency comb or a supercontinuum.

Abstract: A hole-assisted optical fiber includes a core portion and a cladding portion that includes an inner cladding layer, an outer cladding layer, and holes formed around the core portion. A diameter of the core portion is 3 ?m to 9.8 ?m, a relative refractive index difference of the core portion relative to the outer cladding layer is 0.11% to 0.45%, an outside diameter of the inner cladding layer is 53 ?m or less, a relative refractive index difference of the inner cladding layer relative to the outer cladding layer is a negative value, ?0.30% or more, a diameter of each hole is 2.4 ?m to 4.0 ?m, a hole occupancy rate is 17% to 48%, a bending loss at a wavelength of 1625 nm when bent at a radius of 5 mm is 1 dB/turn or less, and a cut-off wavelength is 1550 nm or less.

Abstract: In general, in one aspect, the disclosure features a system that includes a flexible waveguide having a hollow core extending along a waveguide axis and a region surrounding the core, the region being configured to guide radiation from the CO2 laser along the waveguide axis from an input end to an output end of the waveguide. The system also includes a handpiece attached to the waveguide, wherein the handpiece allows an operator to control the orientation of the output end to direct the radiation to a target location of a patient and the handpiece includes a tip extending past the output end that provides a minimum standoff distance between the output end and the target location.

Abstract: The microstructured optical fibre comprises a core (4) surrounded by a sheath (1) comprising a base material having a refraction index (ni) and a plurality of at least two different types of inclusion: a first type of inclusion (2) having a refraction index n2 (n2>n1), and a second type of inclusion (3) having a refraction index n3 (n3<n1). The inclusions (2, 3) are arranged and dimensioned in such a way as to ensure guidance, by total internal reflection (RTI), of a fundamental mode of the light, centred on a wavelength ?RTI, and of a fundamental mode of the light in the first photonic forbidden band (BG1), centred on a wavelength ?BG1, which is different to that ?RTI of the fundamental mode guided by total internal reflection (RTI).

Abstract: Various embodiments include photonic bandgap fibers (PBGF). Some PBGF embodiments have a hollow core (HC) and may have a square lattice (SQL). In various embodiments, SQL PBGF can have a cladding region including 2-10 layers of air-holes. In various embodiments, an HC SQL PBGF can be configured to provide a relative wavelength transmission window ??/?c larger than about 0.35 and a minimum transmission loss in a range from about 70 dB/km to about 0.1 dB/km. In some embodiments, the HC SQL PBGF can be a polarization maintaining fiber. Methods of fabricating PBGF are also disclosed along with some examples of fabricated fibers. Various applications of PBGF are also described.

Abstract: A holey fiber includes a core portion located at a center of the holey fiber, and a cladding portion located around the core portion, the cladding portion having holes formed in layers around the core portion. The holes are arranged so as to form a triangular lattice while d/? is within a range of 0.33 to 0.43, ? is within a range of 10.5 micrometers to 15 micrometers when a hole diameter is d in micrometer and a lattice constant of the triangular lattice is ? in micrometer, and in a wavelength of 1550 nanometer, an effective core-area is equal to or greater than 130 ?m2, a bending loss in a case of bending the holey fiber at a bend diameter of 20 millimeters is equal to or less than 200 dB/m, and the holey fiber demonstrates a single-mode operation.

Abstract: This invention pertains to a holey fiber and to a fabrication method for making the fiber. The holey fiber can transmit light by total internal reflection or by Bragg diffraction, can be single mode or multimode and can have solid core or a hollow core. The holey fiber has outside diameter typically of 20 microns to 5 mm, a hollow core of a diameter typically of 0.2 micron to 150 microns and longitudinal channels therethrough of a diameter typically of 0.1 micron to 150 microns. The channels are disposed in a desired arrangement with center-to-center distance variation of less than about 2% along the length of the fiber and the cross-section thereof is round that varies less than about 2%.

Abstract: An optical fiber includes a cladding with a material having a first refractive index and a pattern of regions formed therein. Each of the regions has a second refractive index lower than the first refractive index. The optical fiber further includes a core region and a core ring having an inner perimeter, an outer perimeter, and a thickness between the inner perimeter and the outer perimeter. The thickness is sized to reduce the number of ring surface modes supported by the core ring.

Abstract: There are provided fiber optic local convergence points (“LCPs”) adapted for use with multiple dwelling units (“MDUs”) that facilitate relatively easy installation and/or optical connectivity to a relatively large number of subscribers. The LCP includes a housing mounted to a surface, such as a wall, and a cable assembly with a connector end to be optically connected to a distribution cable and a splitter end to be located within the housing. The splitter end includes at least one splitter and a plurality of subscriber receptacles to which subscriber cables may be optically connected. The splitter end of the cable assembly of the LCP may also include a splice tray assembly and/or a fiber optic routing guide. Furthermore, a fiber distribution terminal (“FDT”) may be provided along the subscriber cable to facilitate installation of the fiber optic network within the MDU.