Abstract: The present invention relates to an optical fiber for light pulse expansion in which the ratio (?3/?2) of the third derivative ?3 to the second derivative ?2 is negative, the absolute value thereof is large, and the absolute value of the second derivative ?2 is also large. Such an optical fiber comprises at least a central core portion having a maximum refractive index N1 and an outer diameter 2a, a depressed portion, provided on the outer periphery of the central core portion, having a minimum refractive index N2 and an outer diameter 2b, and a cladding portion, provided on the outer periphery of the depressed portion, having a maximum refractive index N3. The respective maximum refractive indices of the central core portion, the depressed portion and the cladding portion satisfy the relationship “N1>N3>N2”.

Abstract: An elongate waveguide for guiding light including a core having an elongate region of relatively low refractive index; a microstructured region around the core comprising elongate regions of relatively low refractive index interspersed with elongate regions of relatively high refractive index; and a boundary at the interface between the core and the microstructured region, the boundary including, in the transverse cross-section, a region of relatively high refractive index, which is connected to the microstructured region at a plurality of nodes, and at least one relatively enlarged region around the boundary, the enlarged region having a major dimension and a minor dimension, wherein the length of the major dimension divided by the length of the minor dimension is more than 3.0.

Abstract: An optical fiber includes a core region and a cladding region. The cladding region includes a first cladding region on outer circumference of the core region, which includes a main-medium region and a sub-medium region having a refractive index lower than that of the main-medium region. The sub-medium region includes a plurality of inner sub-medium regions arranged along the outer circumference of the core region and a plurality of outer sub-medium regions arranged on outer of the inner sub-medium regions. The outer sub-medium regions have a lateral cross section larger than that of the inner sub-medium regions.

Abstract: A method for manufacturing a single mode optical fiber with a reduced PMD (Polarization Mode Dispersion), by drawing an optical fiber preform composed of a core and a clad surrounding the core, includes (a) heating the optical fiber preform to a high temperature using a furnace, and drawing an optical fiber from an outlet of the furnace at a linear velocity (Vf) of 500 mpm or above by means of neck-down drawing; and (b) impressing a spin on the optical fiber by means of a spin impressing device provided on a drawing path of the optical fiber, wherein a maximum spatial frequency of spin (y) impressed on the optical fiber satisfies the following equations Exp ? ( 24 ? t - 12 ) ? y ? - 20 × log ( V f 500 ) + 25 and t=(0.21×CladOval)+(0.04×CoreOval)+(0.17×ECC), where y is a maximum spatial frequency of spin [turns/m], Vf is a drawing velocity [mpm], CladOval is a clad ovality [%], CoreOval is a core ovality [%], and ECC is an eccentricity [?m].

Abstract: Quasi-single mode optical waveguide fibers are disclosed that are bend resistant and capable of providing single mode transmission, for example at wavelengths greater than 1260 nm when the fundamental mode of optical energy is launched into the core of the fiber. Optical fiber line incorporating quasi-single mode optical waveguide fiber is also disclosed. Jumpers, or patchcords, utilizing quasi-single mode optical waveguide fiber are also disclosed herein.

Abstract: An optical fiber comprising: a silica based core having a first index of refraction n1; and at least one silica based cladding surrounding the core, the at least one silica based cladding comprising index lowering non-periodic voids containing a gas, wherein at least 80% of said voids have a maximum cross-sectional dimension of less than 2000 nm, and the NA of the fiber layer situated immediately adjacent to and inside said at least one silica based cladding is at least 0.2.

Abstract: The present invention relates in general to coupling of light from one or more input waveguides to an output waveguide or output section of a waveguide having other physical dimensions and/or optical properties than the input waveguide or waveguides. The invention relates to an optical component in the form of a photonic crystal fiber for coupling light from one component/system with a given numerical aperture to another component/system with another numerical aperture. The invention further relates to methods of producing the optical component, and articles comprising the optical component, and to the use of the optical component. The invention further relates to an optical component comprising a bundle of input fibers that are tapered and fused together to form an input coupler e.g. for coupling light from several light sources into a single waveguide. The invention still further relates to the control of the spatial extension of a guided mode (e.g.

Abstract: An acoustic sensor includes at least one photonic crystal structure having at least one optical resonance with a resonance frequency and a resonance lineshape. The acoustic sensor further includes a housing substantially surrounding the at least one photonic crystal structure and mechanically coupled to the at least one photonic crystal structure. At least one of the resonance frequency and the resonance lineshape is responsive to acoustic waves incident upon the housing.

Abstract: A holey fiber, which has a zero-dispersion wavelength of less than 700 nm and operates as single mode under its zero-dispersion wavelength, is provided. The holey fiber according to the present invention comprises a core region that is formed at a center of the holey fiber; and a cladding region, formed at the circumference of the core region, which has a plurality of holes distributed as triangle lattice around the core region; wherein the holey fiber has a fundamental mode of less than 700 nm, a higher order mode, and the fundamental mode and the higher order mode confinement losses of less than 0.1 dB/m and more than 10 dB/m, respectively, at the zero-dispersion wavelength.

Abstract: The invention relates to methods and apparatuses for guiding and emitting electromagnetic radiation from a fluid waveguide. Various methods for changing optical properties (e.g., refractive index, absorption, and fluorescence) and/or physical properties (e.g., magnetic susceptibility, electrical conductivity, and temperature) of either the waveguide core or the cladding, or both, are provided herein. In one embodiment, electromagnetic radiation is guided and/or emitted at multiple distinct wavelengths, including emission in the form of an essentially continuous band, in some cases covering at least 150 nanometers. In another embodiment, methods for splitting a waveguide core and/or the joining of at least two waveguide cores in a waveguide are provided. In yet another embodiment, the invention includes the use of thermal gradients to generate a waveguide and/or to change the properties of waveguides. Embodiments of the waveguides may be used for optical detection or spectroscopic analysis.

Abstract: A method for fabricating a terahertz waveguide comprises forming a multilayer reflector formed of alternating layers of first and second polymer materials with distinct refractive indices, and defining with the multilayer reflector a hollow core through which terahertz radiation propagates. The corresponding terahertz waveguide comprises the multilayer reflector formed of the alternating layers of the first and second polymer materials with distinct refractive indices, and a hollow core defined by the multilayer reflector and through which terahertz radiation propagates.

Abstract: The present invention relates to a method for manufacturing an optical preform by employing an internal vapor deposition process. The method uses an energy source and a substrate tube, wherein the energy source is movable over the length of the substrate tube between a point of a reversal at the supply side and a point of a reversal at the discharge side.

Abstract: Fiber optic cable systems and methods incorporating a luminescent compound-containing layer to identify cracks. Exemplary embodiments include a fiber optic cable apparatus including a core for receiving laser light emitted from a VCSEL for the detection of faults in the fiber optic cable, a cladding disposed around the core, the cladding having an index of retraction differential with the core thereby allowing containment of light within the core by total internal reflection within the core, a buffer disposed around the cladding, the buffer capable of receiving LED emitted light for the detection of faults in the fiber optic cable, a braiding layer disposed around the buffer and configured to allow LED light to transmit from the buffer, and a jacket disposed around the braiding layer, the jacket having optical properties to receive LED light transmitted down the buffer in response to VCSEL light having been unsuccessfully transmitted down the core.

Abstract: A photonic bandgap fiber includes a hollow core formed along a center axis of the photonic bandgap fiber, through which a light propagates and a cladding region made of silica glass. The cladding region includes air holes forming a triangular lattice arranged around the hollow core. A lattice constant of the triangular lattice of the air holes ? is equal to or smaller than 2.1 ?m. Confinement loss in a predetermined wavelength range including a center wavelength of a photonic bandgap is lower than scattering loss.

Abstract: A fiber Chirped Pulse Amplification (CPA) laser system includes a photonics band gap (PBG) fiber to function as a compressor. The PBG fiber is spliced with a fiber end cap that has an core expander for increasing a mode area of the PBG fiber. With increased mode area, the laser system is enabled to sustain an increased damage threshold energy thus is capable of producing short pulse laser with higher pulse energy.

Abstract: Microstructured optical fiber for single-moded transmission of optical signals, the optical fiber including a core region and a cladding region, the cladding region including an annular hole-containing region that contains non-periodically disposed holes. The optical fiber provides single mode transmission and low bend loss.

Abstract: Photonic crystal structures having a plurality of air columns and coating such structures to provide structures with improved performance are described herein. The coating includes a material that coats an uppermost portion of a photonic crystal structure, wherein the photonic crystal structure comprises a plurality of air columns and wherein the plurality of air columns are coated on their uppermost surface by the coating material.

Abstract: A multicore optical fibre includes a microstructured cladding material formed from a plurality of cladding elements arranged in an array and each cladding element comprising at least two different materials each having different refractive indices, and a plurality of core elements formed within interstitial regions between adjacent cladding elements. A fibre so formed may have a large number of cores per unit cross-sectional area as compared with prior art fibres, and thus allows the fibre to have relatively short distances between adjacent cores for a given required inter-core isolation. A fibre so formed has utility in many areas requiring high core density, such as inter-chip optical communication, or optical communication between circuit boards.

Abstract: A resonator is provided which is produced by a defect formed in a three-dimensional photonic crystal. The three-dimensional photonic crystal can include layers containing a plurality of columnar structures with discrete structures in sublayers.

Abstract: A filled-core optical fiber (100) spliced to conventional, solid core optical transmission fiber (175) and a related method of making the same are provided. The optical fiber (100) comprises a core region (140), a cladding ring (120) enclosing the core region (120), and an outer cladding layer (160). A fill hole (115) is formed in the optical fiber (100) which extends from an outer sidewall (110) to the core region (140). The fill hole (115) is for introducing optical material (165) into the core region (140). The optical material (165) is introduced into the core region (140) after opposing ends (121, 122) of the optical fiber (100) are spliced to the free ends (176, 176) of conventional, solid core optical transmission fiber (175). The optical material (165) is introduced into core region (140) after splicing to avoid damage to the optical material (165) due to exposure to high temperatures generated during splicing.

Abstract: An optical probe assembly includes a light guide that includes a core region and a surrounding cladding region. The core region is constructed so as to minimize the creation of a relatively broadband spurious background noise signal when conveying the Raman pump light to the specimen, and the cladding region is constructed so as to satisfy the wave guiding reflection requirements of the Raman pump light and the Raman signature. A Raman spectroscopy system includes: a laser for producing Raman pump light; an optical probe assembly; and an optical spectrum analyzer for receiving the Raman signature of a specimen and identifying and characterizing the specimen based upon the spectrum of the Raman signature. Related methods are also disclosed.

Abstract: Provided are an apparatus and a method for injecting liquid crystal into a hollow optic fiber. The apparatus includes: a first holder and a second holder each of which has a fluid passage for holding corresponding one end of the hollow optic fiber to be communicated with the fluid passage a container connected to a tube disposed with a valve at the fluid passage of the second holder and storing liquid crystal; an air supplying device connected to the first holder and the container through tubes having a plurality of valves to select an air passage for making the hollow optic fiber vacuous by sucking air out of the hollow optic fiber and forcedly injecting liquid crystal into the hollow optic fiber by supplying an air pressure.

Abstract: An optical device includes a hollow-core photonic-bandgap fiber, wherein at least a portion of the hollow-core photonic-bandgap fiber has a longitudinal axis and is twisted about the longitudinal axis.

Abstract: A holey fiber includes a core region and a cladding region surrounding the core region and having air holes arranged around the core region. The cladding region includes an inner cladding layer surrounding the core region and an outer cladding layer surrounding the inner cladding layer. Furthermore, viscosities of the core region and the inner cladding layer are set lower than a viscosity of the outer cladding layer.

Abstract: Large-mode-area single material holey fiber tapers with collapsed by nonadiabatic process air holes in the waist for fiber optic sensors and a method for manufacturing these tapers are claimed. The gradual collapsing of the holes is achieved by tapering the fibers with a “slow-and-hot” method. This nonadiabatic process makes the fundamental mode of the holey fiber to couple to multiple modes of the solid taper waist. Owing to the beating between the modes, the transmission spectra of the tapered single material holey fibers exhibit several interference peaks. That means the all-fiber Mach-Zehnder type interferometer is formed in a holey fiber such a way. The multiple peaks, combined with a fitting algorithm, allow high-accuracy refractometric measurements, temperature-independent strain measurements, measurements of high temperature and may be used for measuring many others parameters.

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: An optical transmission system employs an optical fiber as an optical transmission path that includes a holey fiber and a dispersion-compensating optical fiber. The holey fiber includes a core region that is formed at a center of the holey fiber and a cladding region having a plurality of holes around the core region at regular intervals. The dispersion-compensating optical fiber is connected close to the holey fiber and that collectively compensates wavelength dispersion of the holey fiber at an operation wavelength in at least two wavelength bands out of O band, E band, S band, C band, and L band within a predetermined range depending on a transmission rate.

Abstract: Photonic crystal sensors may be created from two and three dimensional photonic crystals by introducing defects. The localization of the optical field in the defect region affords the ability to sense small volumes of analyte.

Abstract: A single-mode optical fiber segment incorporating liquid-filled holes parallel to the core that are sealed at each end. Heating the liquid produces stress in the fiber and thereby increases the birefringence level. Alternatively the holes may be filled and sealed at a temperature lower than the temperature at which the fiber will be operated, the temperature difference determining the stress level for given hole characteristics.

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 surrounding the core region and 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: A holey fiber has a core region, a cladding region surrounding the core region, air holes arranged around the core region, and a connection section extending from at least one end portion of the holey fiber. A refractive index of the core region in the connection section is higher than a refractive index of the cladding region without air holes in the connection section.

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 photonic guiding device and methods of making and using are disclosed. The photonic guiding device comprises a large core hollow waveguide configured to interconnect electronic circuitry on a circuit board. A reflective coating covers an interior of the hollow waveguide to provide a high reflectivity to enable light to be reflected from a surface of the reflective coating. A collimator is configured to collimate multi-mode coherent light directed into the hollow waveguide.

Abstract: A method of forming a nanowire is disclosed. In one embodiment, a primary preform is formed comprising at least one central region and a support structure. The primary preform is then drawn to a cane, which is then inserted into an outer portion, to form a secondary preform. The secondary preform is then drawn until the at least one central portion is a nanowire. The method can produce nanowires of far greater length than existing methods, and can reduce the likelihood of damaging the nanowire when handling.

Abstract: Fiber Bragg gratings were written in pure silica photonic crystal fibers and photonic crystal fiber tapers with 125 fs, 800 nm IR radiation. High reflectivites were achieved with short exposure times in the tapers. Both multimode and single mode grating reflections were achieved in the fiber tapers. By tapering the photonic crystal fibers scattering that would otherwise have occurred was lessened and light external to the fiber could reach the core effectively to write a grating.

Abstract: An optical fiber comprising a multimode glass core having a diameter of at least 250 microns and an index of refraction and a polymer cladding having a thickness and contactingly surrounding a glass portion of the fiber so as to define an interface between the glass portion and the polymer cladding. The polymer cladding can have a first index of refraction that is less than the index of refraction. The fiber can comprise a density of less than 0.25 non-conforming regions having a diameter of 25 microns or greater per millimeter of length along the fiber, where each of the non-conforming regions is a region visible to the human eye under an optical microscope and having at least a portion thereof within a selected distance of the interface. The selected distance can be less than or equal to the thickness of the polymer cladding. The optical microscope can have a total magnification of about 200. The polymer cladding can be applied to at least a part of the optical fiber in at least a class 1000 environment.

Abstract: A photonic guiding device and methods of making and using are disclosed. The photonic guiding device comprises a large core hollow waveguide configured to interconnect electronic circuitry on a circuit board. A reflective coating covers an interior of the hollow waveguide to provide a high reflectivity to enable light to be reflected from a surface of the reflective coating. A collimator is configured to collimate multi-mode coherent light directed into the hollow waveguide.

Abstract: A two-dimensional photonic crystal, wherein on a plane in which four adjoining unit lattices L are arranged so as to have one angle in common with the unit lattice L being a rectangle whose shorter side X1 has a length of x1 and whose longer side Y1 has a length of y1, columnar first dielectric regions each having a rectangular cross section whose shorter side X2 has a length of x2 and whose longer side Y2 has a length of y2 are arranged on shorter sides X1 and longer sides Y1 of each rectangular unit lattice L. In this two-dimensional photonic crystal, the first dielectric region is arranged so that the midpoint of the shorter side X1 and the midpoint of the longer side Y1 and the center of the rectangular cross section substantially coincide, and longer sides Y2 of each first dielectric region are substantially parallel to each other.

Abstract: A sealing composition for a photonic crystal fiber which comprises a compound represented by the following general formula (I), a compound represented by the following general formula (II) and a photo-polymerization initiator: Tf1-(O)a—(CH2)b—(CF2)m—(CH2)b—(O)a-Tf1 (I) Tf2-(O)a—(CH2)b—(CF2)m—(CH2)b—(O)a-Tf2 (II) wherein a represents 0 or 1, b represents 0 or 1, m represents an integer of 4 to 12, Tf1 represents a glycidyl group, and Tf2 represents CH2?CH—C(O)—; and a method for producing an optical fiber comprising filling air holes with above sealing composition and polishing and end surface; and an optical fiber having air holes in the inside which is produced by the method. The above sealing composition can achieve a low refractive index, and also is excellent in the low viscosity and heat resistance, and exhibits good filling characteristics and good polishing processability.

Abstract: A light receiving apparatus connects light to a light receiving device through a tube-type waveguide for making uniform the light intensity distribution of light. The light receiving apparatus is capable of stably receiving optical data even if partiality occurs in the NFP of the light emitted from an end of an optical fiber or even if the partiality of the NFP fluctuates.

Abstract: A method of manufacturing a holey fiber includes forming a preform and drawing the preform. The forming includes arranging a core rod at a center of a jacket tube and arranging capillary tubes having hollows around the core rod inside the jacket tube. The drawing includes heat melting the preform in a heating furnace while controlling at least one of a gas pressure to be applied to insides of the hollows of the capillary tubes, a temperature of the heating furnace, and a drawing speed, based on a structure of air holes to be formed in a first layer from the core region.

Abstract: An optical fiber, comprising: a core with a first refractive index (n1); a silica based outer cladding surrounding the core, the outer cladding having a refractive index (n), such that the core is substantially surrounded by a gap situated between the core and the outer cladding, the gap containing at least one support structure adjacent to the outer cladding and situated between the outer cladding and the core, wherein the support structure is either hollow or gas filed and is not connected to any other support structure situated within the gap.

Abstract: The present invention provides methods of generating short wavelength radiation, methods of transporting short wavelength radiation, and apparati used in these methods. One embodiment of the invention provides a method of transporting short wavelength radiation using a photonic band gap fiber. Another embodiment of the invention provides a method of transporting short wavelength radiation using a bundle of photonic band gap fibers. Another embodiment of the invention provides a method of generating ultraviolet radiation using high harmonic generation by pumping a noble gas-filled photonic band gap fiber with a pulsed laser source.

Abstract: A polarization-maintaining optical fiber includes a core region and a cladding region formed around the core region. The cladding region has a refractive index lower than a refractive index of the core region. A refractive index profile of the core region is either one of a step shaped or a concave shaped. The cladding region includes two holes formed in such a manner that a shortest distance from the core region is virtually zero at locations in opposite to each other across the core region.

Abstract: An optical fiber includes a core, a clad formed around the core, a plurality of holes being formed in the clad, and a hardening resin having a moisture permeability equal to or less than 0.5 g/cm2·24 hr, in which the hardening resin is filled in a vicinity of an end face of the holes.

Abstract: A large mode area optical fiber is configured to support multiple transverse modes of signal radiation within its core region. The fiber is a hybrid design that includes at least two axial segments having different characteristics. In a first axial segment the transverse refractive index profile inside the core is not radially uniform being characterized by a radial dip in refractive index. The first segment supports more than one transverse mode. In a second axial segment the transverse refractive index profile inside the core is more uniform than that of the first segment. The two segments are adiabatically coupled to one another. Illustratively, the second segment is a terminal portion of the fiber which facilitates coupling to other components. In one embodiment, in the first segment M12>1.0, and in the second segment M22<<M12. In a preferred embodiment, M12>>1.0 and M22˜1.0. In another embodiment, the optical fiber is coupled to a fiber stub.

Abstract: Microstructured optical fiber and method of making. Glass soot is deposited and then consolidated under conditions which are effective to trap a portion of the consolidation gases in the glass to thereby produce a non-periodic array of voids which may then be used to form a void containing cladding region in an optical fiber. Preferred void producing consolidation gases include nitrogen, argon, CO2, oxygen, chlorine, CF4, CO, SO2 and mixtures thereof.

Abstract: A method of making an optical fiber article can include providing an optical fiber including at least a core; providing a preform; and subsequent to the foregoing providing of the optical fiber and the preform, drawing the preform so as to dispose a region about the optical fiber. An optical fiber article can include a core; a pump cladding disposed about the core, the pump cladding for propagating pump light; and a second cladding disposed about the pump cladding, where the second cladding can provide a photonic bandgap for tending to confine pump light to a region about which the second cladding is disposed. The second cladding can comprise a plurality of layers including a first layer having a different optical property than a second layer, and the plurality of layers can be arranged as to provide the photonic bandgap effect.

Abstract: Optical waveguide fiber that is bend resistant and single moded at 1260 nm and at higher wavelengths. The optical fiber includes a core and cladding, the cladding having an annular inner region, an annular ring region, and an annular outer region. The annular ring region has a low relative refractive index.

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.