Abstract: A microstructured optical fibre comprising an inner cladding and an outer cladding; said outer cladding comprising elongated outer cladding features extending in an axial direction of the fibre, and at least one cladding recess extending at least partly through the outer cladding in a radial direction to the inner cladding; said cladding recess providing optical access to the inner cladding; a method of forming a cladding recess in such an optical fibre comprising a step of collapsing a part of the outer cladding features by use of a heat source; an apparatus comprising such a microstructured optical fibre, preferably a laser or an amplifier.

Abstract: A coupling optical system for coupling light into an optical fiber of an optical communications system includes a liquid that includes a dispersion of microscopic particles and two transparent media that hold the liquid between them along an optical axis. The refractive power of the liquid is variable according to the electromagnetic field applied to the liquid to vary the migration of the microscopic particles of the dispersion within the liquid. The position of a light collecting point of the coupling optical system is adjustable based on the variation in the refractive power of the liquid so that light can be efficiently coupled into optical fibers at different distances along the optical axis from the coupling optical system. At the light collecting point, the end surface of an optical fiber collects light from a light source or another optical fiber. One or more collimator lenses may help converge the light.

Abstract: A photonic bandgap assembly used in a laser device for generating a near-diffraction-limited optical beam that comprises simultaneous multiple wavelengths. The photonic bandgap fiber assembly has a plurality of serially connected segments each having a photonic crystal fiber each being designed to efficiently perform Raman conversion on a pump wavelength to a near-diffraction-limited output wavelength. A first segment of the assembly is connected to a pump laser, and the output wavelength generated by each segment is output to the following segment to serve as a pump beam of the photonic crystal fiber thereof. Therefore, the pump beam is converted in a plurality of output beams with different wavelengths. The output beams can then be selectively recombined and coupled out as a multiple-wavelength optical beam.

Abstract: The invention relates to a light emitting device consisting of one or more light sources coupled to a light guide containing diffuser particles having a refractive index close to the refractive index of the core of the light guide. The diffuser particles cause a scattering of the light emitted from the light sources so that light emitted from the light emitting device has colour variation imperceptible to the human eye and small and gradual variations in intensity.

Abstract: A confocal microscope comprises a light source unit having at least two light sources which generate lights having different wavelengths, an objective lens which condenses light from the light source unit on a sample, a light scanning unit which scans the light form the light source unit on the sample two-dimensionally, and a photonic crystal fiber which is disposed between the light source unit and the light scanning unit, and which propagates the light led from the light source unit to the light scanning unit side, wherein the photonic crystal fiber has a plurality of air holes arranged at a clad provided at a periphery of a core.

Abstract: Embodiments include a fiber optic laser system having at least one optical waveguide with a laseable core and a pump cladding disposed adjacent the lasing core. A source of electromagnetic pumping energy is disposed adjacent to the optical waveguide and has an emission axis that is directed toward the optical waveguide. An optically reflective surface is disposed towards the optical waveguide and may be configured as an enclosure disposed about at least a portion of the optical waveguide. An index matching material may be disposed within the enclosure and in contact with at least a portion of the optical waveguide.

Abstract: The present invention relates to an optical fiber having a configuration which enables utilization of nonlinear phenomena in the near-infrared region. The optical fiber is directed to a holey fiber having a core region extending along a predetermined axis and a cladding region with plural holes arranged along the core region. The plural holes are arranged to constitute plural layers about the core region in the cross-section orthogonal to the predetermined axis. The three holes constituting the first layer (the innermost layer) closest to the core region correspond to three vertexes from among the six vertexes of a regular hexagon and are placed such that the arrangement of the three holes has three-fold rotational symmetry. The optical fiber enables utilization of nonlinear phenomena in the near-infrared region, by properly adjusting the hole diameter d and the pitch L between adjacent holes from among the holes constituting a single layer.

Abstract: A liquid core waveguide photon energy material processing system is provided. The system includes a photon energy source configured to generate a high intensity photon beam for material processing. The system also includes a liquid core waveguide configured to transmit the high intensity photon beam towards at least one object for material processing. The liquid core waveguide in-turn includes a liquid core having a first refractive index and a cladding element having a second refractive index and configured to guide the liquid core, wherein the first refractive index is higher than the second refractive index. The system further includes a liquid source configured to generate the liquid core. The liquid core includes a liquid solution.

Abstract: An optoelectric converting substrate includes a substrate, at least one honeycomb-shaped micro-structured optical waveguide embedded in the substrate and having two ends exposed through the substrate, a plurality of optoelectronic elements disposed on the substrate and coupled with the two ends of the honeycomb-shaped micro-structured optical waveguide, and a plurality of IC driving elements disposed on the substrate and electrically connected with the optoelectronic elements by conductive wires to drive the optoelectronic elements such that optical signals are transmitted through the honeycomb-shaped micro-structured optical waveguide. The optoelectric converting substrate can be easily fabricated at a low cost and effectively increases the displacement tolerance of the optoelectronic elements in substrate packaging.

Abstract: A fluidic waveguide comprising a container and a fluid that fills said container, wherein said fluid has a refractive index greater than the refractive index of the wall of said container and wherein said fluid can act as a waveguide for electromagnetic radiation when contacted therewith is disclosed. A corresponding fluidic lightguide along with devices that function as composite waveguides and lightguides are described. Assays utilizing this waveguide for biochemical, chemical, and other kinds of analyzes are also disclosed.

Abstract: Included among the many structures described herein are photonic bandgap fibers designed to provide a desired dispersion spectrum. Additionally, designs for achieving wide transmission bands and lower transmission loss are also discussed. For example, in some fiber designs, smaller dimensions of high index material in the cladding and large core size provide small flat dispersion over a wide spectral range. In other examples, the thickness of the high index ring-shaped region closest to the core has sufficiently large dimensions to provide negative dispersion or zero dispersion at a desired wavelength. Additionally, low index cladding features distributed along concentric rings or circles may be used for achieving wide bandgaps.

Abstract: The present invention concerns an optical sensor located on a preferred azimuthal portion of the side of an optical fiber. An optical fiber having two opposite ends, a core and a cladding and at least one sensing area is disclosed. Each of the sensing areas is located between the two opposite ends and each has a longitudinal, a radial and an azimuthal portion of the fiber that has been removed and replaced by a sensing material. The sensing collected light is thus representative of a parameter to be measured, such as temperature. Placing the sensing material in a lateral side portion of the fiber increases the sensitivity of the sensor, particularly when it comes to contact temperature measurement in vivo.

Abstract: An optical fiber, comprising: (i) a rare earth doped silica based elongated core with a first refractive index (n1) with an aspect ratio of 1:5 to 1; (ii) a silica based moat abutting and at least substantially surrounding the core, the moat having a refractive index n2, wherein n2<n1; (iii) a silica based inner cladding surrounding the moat, the inner cladding having a third refractive index (n3), wherein n1>n3; and n3>n2; (iv) a silica based outer cladding surrounding said inner cladding, the outer cladding having a fourth refractive index (n4), such that n4<n3; the optical fiber exhibits single polarization at the operating wavelength band.

Abstract: A two-mode photonic crystal fiber includes a core of a substantially transparent core material. The core material has a core refractive index and a length, and has a core diameter. The fiber also includes a cladding region surrounding the length of core material. The cladding region has a first substantially transparent cladding material, having a first refractive index. The first substantially transparent cladding material has embedded along its length a substantially periodic array of holes, having a diameter, d, and being spaced apart by a pitch, ?. The holes have a second refractive index, which is less than the first refractive index. The dimensions of the hole diameter, d, and the pitch, ?, co-operate to give two modes propagation within the photonic crystal fiber independent of input radiation wavelength for any value of the pitch, ?, for a substantially fixed d/? ratio within a range of approximately 0.45–0.65.

Abstract: In general, in one aspect, the disclosure features a fiber waveguide having a waveguide axis, including a core extending along the waveguide axis and a confinement region extending along the waveguide axis surrounding the core. The confinement region includes a periodic structure along a radial direction extending from the waveguide axis and each period in the periodic structure includes a layer of a chalcogenide glass and a layer of a polymer.

Abstract: A gap-soliton structure is provided. The gap-soliton structure includes a cladding structure having alternating layers of different index values. A core region is interposed between the alternating layers of index values. The core or the cladding structure includes one or more nonlinear materials so as to achieve gap-soliton bistability.

Abstract: The invention relates to a micro-structured fiber comprising a core region and a cladding region. The cladding region has a plurality of air holes regularly arranged on a plurality of rings, wherein the innermost ring of the fiber defines the core region. The cladding region comprises an inner circumference portion and an outer circumference portion; the inner circumference portion comprises at least one ring, the outer circumference portion comprises at least one ring, wherein the diameter of the air hole on the outer circumference portion is larger than that of the air hole on the inner circumference portion. As a result, the micro-structured fiber of the present invention has the advantages of broader band of nearly zero dispersion, less confinement loss, being easier to design due to less geometrical parameters needed to be optimized, and being easier to fabricate.

Abstract: Techniques and devices based on holey fibers with internal holes that confine a gas medium for various applications.

Abstract: The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode waveguide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

Abstract: In an optical device, a slab layer has an active layer sandwiched between two cladding layers. Periodic air holes are present in the slab layer. A linear defect region is present in a part of the air hole structures. As a result, laser oscillation is generated at the band end in a two-dimensional photonic crystal waveguide mode.

Abstract: An optical fiber for transmitting light, said optical fiber having an axial direction and a cross section perpendicular to said axial direction, said optical fiber comprising: (1) a first core region comprising a first core material having a refractive index Nco,1; (2) a microstructured first cladding region surrounding the first core region, said first cladding region comprising a first cladding material and a plurality of spaced apart first cladding features or elements that are elongated in the fiber axial direction and disposed in the first cladding material, said first cladding material having a refractive index Ncl,1 and each said first cladding feature or element having a refractive index being lower than Ncl,1, whereby a resultant geometrical index Nge,cl, 1? of the first cladding region is lowered compared to Ncl,1; (3) a second core region surrounding said first cladding region, said second core region comprising a second core material having a refractive index Nco,2, and (4) a second cladding regio

Abstract: An optical fiber cable has an optical fiber core wire and a tension member. The tension member is formed of a glass fiber reinforced resin linear material with glass fibers and a matrix resin, and satisfies the following requirements: (1) (EfVf+EmVm)d2?8.3/n wherein Ef represents the modulus of elasticity of glass fibers, GPa; Vf represents the content of glass fibers, %/100; Em represents the modulus of elasticity of matrix resin, GPa; Vm represents the content of matrix resin, %/100; d represents the diameter of tension member, mm; and n represents the number of tension members used in optical fiber cable; (2) (Ef/Em)?22; (3) Vf=0.6 to 0.88; and (4) an elongation at break of glass fibers of not less than 5% and an elongation at break of matrix resin of not less than 5%.

Abstract: Single transverse mode fiber amplifier and laser operation is obtained with a multi-mode signal core surrounded by cladding containing irregular microstructuring that causes loss in all of the core modes except the fundamental while maintaining robust guiding of the fundamental mode resulting in higher fiber laser power capacity.

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 pressure transducer has a cane waveguide geometry with “side-holes” in the cane waveguide cross-section that reduce the force required to compress the waveguide. The cane waveguide is a large diameter optical waveguide with a cross-section of at least about 0.3 millimeters, at least one inner core, a Bragg grating arranged therein, a cladding surrounding the inner core, and a structural configuration for providing a reduced bulk modulus of compressibility and maintaining the anti-buckling strength of the waveguide. The structural configuration reduces the cross-sectional area of the waveguide. These side holes reduce the amount of glass that needs to be compressed, but retains the large diameter. The waveguide responds to an optical signal, further responds to an external pressure that causes a differential strain across the inner core, for providing a Bragg grating optical-signal containing information about a birefringence of the Bragg grating that is proportional to the external pressure.

Abstract: To overcome problems of fabricating conventional core-clad optical fibre from non-silica based (compound) glass, it is proposed to fabricate non-silica based (compound) glass optical fibre as holey fibre i.e. one contining Longitudinal holes in the cladding. This removes the conventional problems associated with mismatch of the physical properties of the core and clad compound glasses, since a holey fibre can be made of a single glass composition. With a holey fibre, it is not necessary to have different glasses for the core and cladding, since the necessary refractive index modulation between core and cladding is provided by the microstructure of the clad, i.e. its holes, rather than by a difference in materials properties between the clad and core glasses. Specifically, the conventional thermal mismatch problems between core and clad are circumvented.

Abstract: A preform for a microstructured fibre or a part for a preform for a microstructured fibre. The preform or part has a length in the longitudinal direction and a cross section perpendicular thereto, and includes a rod arranged at the centre of the preform or part, with one or more tubes being concentric to the rod. The rod is sleeved inside a first of the concentric tubes, and the rod and/or at least one of the concentric tubes has grooves and/or slits extending in the longitudinal direction, with the number of innermost longitudinally extending grooves and/or slits with respect to a centre of the preform or part being at least six.

Abstract: In one aspect, the invention features a fiber waveguide having a waveguide axis, including a first portion extending along the waveguide axis, and a second portion different from the first portion extending along the waveguide axis surrounding the first portion, wherein at least one of the first and second portions comprises a chalcogenide glass selected from the group consisting of Selenium chalcogenide glasses and Tellurium chalcogenide glasses, both the first and second portions have a viscosity greater than 103 Poise at some temperature, T, and the fiber waveguide is a photonic crystal fiber.

Abstract: A modified photonic crystal fiber yielding a higher peak power for a given maximum intensity. The multi-mode signal core has a depressed index of refraction that pushes the mode distribution to the core edges while a pattern of larger air holes is used to flatten the mode distribution. The core is further surrounded by tuned cladding elements defined by a pattern of smaller air holes that cause loss in all of the core modes except the fundamental while maintaining robust guiding of the fundamental mode.

Abstract: Holey optical fibers (e.g. photonic fibers, random-hole fibers) are fabricated with quantum dots disposed in the holes. The quantum dots can provide light amplification and sensing functions, for example. When used for sensing, the dots will experience altered optical properties (e.g. altered fluorescence or absorption wavelength) in response to certain chemicals, biological elements, radiation, high energy particles, electrical or magnetic fields, or thermal/mechanical deformations. Since the dots are disposed in the holes, the dots interact with the evanescent field of core-confined light. Quantum dots can be damaged by high heat, and so typically cannot be embedded within conventional silica optical fibers. In the present invention, dots can be carried into the holes by a solvent at room temperature. The present invention also includes solid glass fibers made of low melting point materials (e.g. phosphate glass, lead oxide glass) with embedded quantum dots.

Abstract: A tetragonal lattice is formed by first cylindrical structural members, and a photonic crystal has a periodical structure formed by a periodical arrangement of such tetragonal lattice. A distance between center points of the first cylindrical structural members is taken as a unit length a, which constitutes a lattice constant of the tetragonal lattice. At an approximate center of the tetragonal lattice, a cylindrical structural member is provided, and a dielectric area is provided around the first cylindrical structural members and the second cylindrical structural member. This structure allows the formation of a photonic band gap for a TE wave and a photonic band gap for a TM wave in a certain common frequency region, thereby forming a complete band gap.

Abstract: An optical fiber for communications systems, the fiber being designed to ensure a compensation of Kerr effects. The fiber has a profile which ensures that changes in power produce changes in distribution of power between core and cladding, such that the phase change associated with the changed spatial distribution of the power, is equal and opposite to the phase change due to Kerr Effect.

Abstract: An optical fibre device based on the Raman effect comprises a first optical source to provide light at a first wavelength, and a holey optical fibre which receives the light from the first optical source such that optical gain or loss is provided at a second wavelength by the effect of Raman scattering within the fibre. For optical gain, the second wavelength is longer than the first wavelength, and the device can be operated as an amplifier, or as a laser if optical feedback is provided. For optical loss, the second wavelength is shorter than the first, and the device may be used as an optical modulator. The fibre may be fabricated from pure silica, although other undoped or doped materials may alternatively be used to tailor properties of the fibre such as gain spectrum, bandwidth, power handling capability and mode propagation.

Abstract: An optical waveguide in the form of an optical fibre (10) having at least one longitudinally extending light guiding core region (11) composed at least in part of a polymeric material, a longitudinally extending core-surrounding region (12) composed of a polymeric material, and a plurality of light confining elements (15), such as, for example, channel-like holes, located within the core surrounding region. The light confining elements extend in the longitudinal direction of the core region and are distributed about the core region, and at least a majority of the light confining elements having a refractive index less than that of the polymeric material from which the core-surrounding region is composed. A preform for use in manufacture of the optical waveguide is also disclosed.

Abstract: A fresenel zoned microstructured optical fiber is described. The fiber is constructed of concentric zones, each zone being defined by discontinuities in the refractive index. The refractive index within each zone may either be constant or may vary, for example each zone being a section of a parabola or hyperbola. The fiber may be used as a lens, for example for coupling light between fibers with different core sizes.

Abstract: Coupling of core modes to surface modes in an air-core photonic-bandgap fiber (PBF) can cause large propagation losses. Computer simulations analyze the relationship between the geometry and the presence of surface modes in PBFs having a triangular hole pattern and identify ranges of core characteristic dimensions (e.g., radii) for which the fiber supports no surface modes (i.e., only core modes are present) over the entire wavelength range of the bandgap. In particular, for a hole spacing ? and a hole radius ?=0.47?, the core supports a single mode and supports no surface modes for core radii between about 0.68? and about 1.05?. The existence of surface modes can be predicted simply and expediently by studying either the bulk modes alone or the geometry of the fiber without requiring a full analysis of the defect modes.

Abstract: The present invention relates to a plastic photonic crystal fiber for terahertz wave transmission and a method for the manufacturing thereof. More particularly, the present invention is directed to a plastic photonic crystal fiber that can be easily manufactured and has low loss characteristics to be used as a waveguide of terahertz waves. The plastic photonic crystal fiber includes a crystal defect component having a longitudinal axis and a photonic crystal component surrounding the crystal defect component. The photonic crystal component has an array of a plurality of plastic elements having longitudinal axes and forming a 2-dimensional photonic crystal structure with a predetermined lattice constant. Further, the plastic photonic crystal fiber of the present invention can be used as a preform from which a plastic photonic crystal fiber for an optical communication (400–800 nm) can be drawn.

Abstract: An apparatus and method for a transport. The transport including a waveguide including a guiding region and one or more bounding regions for enhancing containment of transmitted radiation within the guiding region, a portion of the waveguide defining a plurality of voids; and a gas disposed in the plurality of voids to enhance an influencer response attribute of the waveguide. A method of operating the transport includes: a) propagating a radiation signal through a waveguide including a guiding region and one or more bounding regions for enhancing containment of transmitted radiation within the guiding region, a portion of the waveguide defining a plurality of voids; and b) enhancing a response of the radiation signal to an influencer applying an influence on the waveguide using a gas disposed in the plurality of voids.

Abstract: A photonic crystal and a producing method thereof are provided. The photonic crystal includes at least two media of different refractive indices formed on a semiconductor substrate. One of the media is periodically arranged in another one of the media. The photonic crystal has a cleaved surface on its side. The directions of primitive translation vectors representing the periodic arrangement directions of the one medium are at desired angles with the cleaved surface. Preferably, the direction of at least one of the primitive translation vectors is in parallel with the cleaved surface.

Abstract: When a piezoelectric element 3 applies an external force to a plastic photonic crystal, the photonic crystal deforms, and accordingly, the photonic band gap easily changes. When the photonic band gap changes, transmission of light with a specific wavelength is limited. Therefore, light with a desired wavelength is outputted from the photonic crystal 2 upon sufficient tuning, and extracted to the outside through an output window 6. In the present invention, a plastic photonic crystal 2 which can achieve sufficient wavelength tuning although it is small is used, and elements are unitized, so that the entire wavelength tunable light source unit is downsized.

Abstract: A flexible hollow waveguide for high efficiency transmission of laser light, comprising: (a) metal cladding tube having interior surface; and (b) elongated bent ribbon of a substrate material; said ribbon having concave interior surface and convex exterior surface and first and second edges therebetween; said ribbon is positioned in said metal cladding tube; said interior surface of the metal cladding tube engaging the said convex exterior surface of the ribbon to hold said first and second edges together and to define an elongated seam therebetween; and (c) first metal layer on the said concave interior surface of the said ribbon; said first metal layer having a elongated discontinuity defined by the said seam; and (d) seamless light reflective second metal layer formed on top of the first metal layer; and (e) seamless light-reflectivity enhancing dielectric layer formed on top of the said second metal layer.

Abstract: An optical fiber having a length can include a core and at least one cladding disposed about the core, where the one cladding can comprise at least first volumetric regions having a first refractive index n1 and second volumetric regions having a second refractive index n2, different from n1, and the first and second volumetric regions in any cross-section taken through the fiber can be randomly intermingled with one another, where the random intermingling of the first and second volumetric regions changes with changes in the location of the cross-section along the length of the fiber.

Abstract: An optical element comprising a periodic structure in which a refractive index is distributed periodically and a deforming portion, which mechanically deforms by an external action, wherein the deforming portion is integrally arranged with the periodic structure along the periodic direction of the periodic structure, and is constructed so as to change the periodicity of the periodic structure by deforming in the periodic direction of the periodic structure. A periodicity of the periodic structure (photonic band structure) in which the refractive index changes periodically can be controlled with a simple configuration.

Abstract: An optical fibre for transmission of light at a predetermined wavelength, the fibre having a core region, an inner cladding region and an outer cladding region, the inner cladding region having spaced apart voids, at least some of which are at least partly filled with a fluid substance to modify a refractive index in the cross-section of the fibre. The fluid substance may be introduced by preparing and fixing the fibre ends, identifying the voids to be filled and infusing the fluid therein while masking openings in the remaining voids. By selective heating of parts of the fibre, the location of the fluid substance in the void may be controlled to extend over only a fraction of the length of a void that extends the length by the fibre.

Abstract: A tunable optical filter has a large diameter cane waveguide with “side-holes” in the cane cross-section that reduce the force required to compress the large diameter optical waveguide without overly compromising the buckling strength thereof. The large diameter optical waveguide has a cross-section of at least about 0.3 millimeters, including at least one inner core, a Bragg grating arranged therein, a cladding surrounding the inner core, and a structural configuration for providing a reduced bulk modulus of compressibility and maintaining the anti-buckling strength of the large diameter optical waveguide. The structural configuration reduces the cross-sectional area of the large diameter optical waveguide. These side holes reduce the amount of glass that needs to be compressed, but retains the large diameter.

Abstract: Method for manufacturing of an optical fiber with a decoupling interface for scattered light to monitor the power of light guided through the optical fiber, where the optical fiber has a core having a first refractive index and a cladding surrounding the core, the cladding having a second refractive index smaller than the first refractive index, and where a portion of the optical fiber is substantially straightly aligned in the region of the decoupling interface, in which method the optical fiber is electro-thermally treated at an intermediate position within the substantially straightly aligned portion such that a partial mixture of core material and cladding material and, thereby, formation of scattering centers occurs in an interface region between the core and said the cladding, thereby forming the decoupling interface for scattered light from the modified intermediate position.

Abstract: A microchip includes a clad layer having a channel through which a sample flows, and an optical waveguide formed within the clad layer and having a higher refractive index than the clad layer. The optical waveguide is formed to act on the channel optically. Thus, the sample flowing in the channel can be analyzed with high accuracy even in the microchip having a fine structure.

Abstract: Holey optical fibers (e.g. photonic fibers, random-hole fibers) are fabricated with quantum dots disposed in the holes. The quantum dots can provide light amplification and sensing functions, for example. When used for sensing, the dots will experience altered optical properties (e.g. altered fluorescence or absorption wavelength) in response to certain chemicals, biological elements, radiation, high energy particles, electrical or magnetic fields, or thermal/mechanical deformations. Since the dots are disposed in the holes, the dots interact with the evanescent field of core-confined light. Quantum dots can be damaged by high heat, and so typically cannot be embedded within conventional silica optical fibers. In the present invention, dots can be carried into the holes by a solvent at room temperature. The present invention also includes solid glass fibers made of low melting point materials (e.g. phosphate glass, lead oxide glass) with embedded quantum dots.

Abstract: A dispersion shifter fiber, which has zero dispersion wavelength on a long wavelength side beyond 1640 nm, a wavelength dispersion of ?1.0 to ?10.0 ps/nm/km at a wavelength range of 1530–1625 nm, a dispersion slope of less than 0.07 ps/nm2/km, a polarization mode dispersion of not more than 0.1 ps/(km)1/2 at a wavelength of 1550 nm, and a core cross-sectional area of 40–70 ?m2 at the wavelength of 1550 nm.

Abstract: A polarization-maintaining optical fiber and absolutely single-polarization optical fiber are provided which enable long distance transmission maintaining a polarization state of signal light. The polarization-maintaining optical fiber includes a core, photonic crystal cladding, and jacket. The photonic crystal cladding is divided into four segments by broken lines from the center to the periphery. Among a plurality of grating holes in a pair of segments opposed to each other with respect to the core, the diameter of grating holes close to the core is greater than the diameter of grating holes in another pair of segments opposed with each other, and than a grating constant.