Abstract: An optical fiber includes: a core at a center; a first cladding layer; a second cladding layer; and a third cladding layer. A maximum refractive index of the core is greater than any of maximum refractive indices of the first cladding layer, the second cladding layer, and the third cladding layer, and the maximum refractive index of the second cladding layer is smaller than any of the maximum refractive indices of the first and the third cladding layer. Additionally, a ratio of a2/a1 is not less than about 2.5 and not more than about 4.5, where a1 represents the radius of the core, and a2 represents the radius of an outer periphery of the first cladding layer, and a relative refractive index difference of the core with respect to a maximum refractive index of the third cladding layer is not less than 0.20% and not more than 0.70%.

Abstract: In an optical transmission path including multimode optical fibers, modal dispersion is reduced so that signal light can be transmitted at high speed and across a broad band, at low-cost and over a long distance. To reduce modal dispersion, when the transmission path is constructed by coupling a plurality of multimode optical fibers, a length ratio for the multimode optical fibers that obtains the maximum band of the optical transmission path is determined, and the multimode optical fibers are coupled according to this length ratio. The multimode optical fibers that are used have specific refractive index profiles as mode dispersion-compensating fibers. The compensated fiber and the mode dispersion-compensating fiber are coupled with specific lengths.

Abstract: An optical fiber coating die is made such that an interfacial shear rate of the optical fiber to the resin coat is calculated in accordance with a pressure value of resin inside a coating cup, and the interfacial shear rate is in a range of ?1.5×105 to 0 sec?1. Also, an optical fiber drawing die is made such that the interfacial shear rate of the optical fiber to the resin coat is calculated in accordance with a diameter of a coating resin, and the interfacial shear rate is in a range of range of ?3×105 to 2×105 sec?1. By doing this, an optical fiber drawing die which can be used in an optical fiber drawing method so as to realize stable resin coating operation even in high-speed drawing operation and high productivity can be realized.

Abstract: In order to provide a dispersion-compensating optical fiber able to be applied over a broad wavelength band, having a large effective area, and as a result, suppressing the occurrence of non-linear effects, the present invention comprises a dispersion-compensating optical fiber that compensates chromatic dispersion of a 1.3 ?m single-mode optical fiber over the entire wavelength range of 1.53-1.63 ?m characterized in that, chromatic dispersion at a wavelength of 1.55 ?m is ?50 ps/nm/km or less, the dispersion slope is negative over the entire wavelength range of 1.53-1.63 ?m, a cutoff wavelength is provided at which there is substantially single-mode propagation, bending loss is 30 dB/m or less, effective area is 20 ?m2 or more, and the absolute value of chromatic dispersion during compensation of the chromatic dispersion of a 1.3 ?m single-mode optical fiber serving as the target of compensation is 0.5 ps/nm/km or less.

Abstract: A method of measuring polarization mode dispersion of an optical fiber includes inputting linearly polarized pulse light into an optical fiber, separating the input linearly polarized light from backscattered light from the optical fiber, detecting a light intensity of the backscattered light as time series data since the generation of the pulse light, calculating a fluctuation of the detected light intensity in the time series data, and evaluating polarization mode dispersion in the optical fiber, based on the calculated fluctuation value.

Abstract: An LED lighting apparatus which comprises an LED chip, and a light-emitting layer which is disposed on a light-emitting side of the LED chip and including an organic fluorescent substance and a matrix containing, as a main component, a fluorine-based or cyanobiphenyl-based liquid crystalline compound exhibiting a nematic phase.

Abstract: The present invention is to provide anthocyanin pigments with improved heat-resistance and production thereof, and a method for coloring foods with said anthocyanin pigments and foods colored with said anthocyanin pigments. Heat-resistance in anthocyanin pigments is enhanced by adjusting an aqueous anthocyanin solution to a pH range of 4.0 to 6.5 at a temperature of 40 to 100° C.

Abstract: A method for fabricating a porous silica preform includes the steps of supplying fuel gas for generating an oxyhydrogen flame to a glass synthesizing burner; supplying Gas A containing silicon and Gas B containing fluorine to the burner; synthesizing glass particles; and depositing the glass particles around a starting rod, in which when glass particles are deposited directly on the starting rod, a supply of Gas A and a supply of Gas B supplied to the burner are adjusted so that a ratio of the number of fluorine atoms to the number of silicon atoms in the gas supplied to the burner satisfies the following Formula (1): {(number of F atoms)/(number of Si atoms)}?0.

Abstract: A single-mode optical fiber has a core and a cladding, and is produced in such a way that, when the radii of layers having individual refractive indexes are varied, more than one optical properties of the core, for example, the effective core area Aeff and the dispersion slope exhibit respective limiting values within a specific range of a reference radius. Such optical fibers provide basically the same optical properties but enable to vary the chromatic dispersion within a specific range so that the single-mode optical fiber is ideally suited for use in high-speed and large capacity communication systems.

Abstract: A higher order mode dispersion compensating fiber includes an optical fiber and a first loss layer which is provided within the fiber and which attenuates a lower order mode propagating through the optical fiber while not attenuating a higher order mode which is higher than the lower order mode. A dispersion compensating fiber mode converter for a higher order fiber includes a single mode fiber; a higher order mode dispersion compensating fiber; and a fused and extended portion which has been formed by fusing and extending the single mode fiber and the higher order mode fiber. The fused and extended portion converts between the LP01 mode of the single mode fiber and the LP02 mode of the higher order mode dispersion compensating fiber.

Abstract: In order to provide a dispersion-compensating optical fiber able to be applied over a broad wavelength band, having a large effective area, and as a result, suppressing the occurrence of non-linear effects, the present invention comprises a dispersion-compensating optical fiber that compensates chromatic dispersion of a 1.3 &mgr;m single-mode optical fiber over the entire wavelength range of 1.53-1.63 &mgr;m characterized in that, chromatic dispersion at a wavelength of 1.55 &mgr;m is −50 ps/nm/km or less, the dispersion slope is negative over the entire wavelength range of 1.53-1.63 &mgr;m, a cutoff wavelength is provided at which there is substantially single-mode propagation, bending loss is 30 dB/m or less, effective area is 20 &mgr;m2 or more, and the absolute value of chromatic dispersion during compensation of the chromatic dispersion of a 1.3 &mgr;m single-mode optical fiber serving as the target of compensation is 0.5 ps/nm/km or less.

Abstract: An optical fiber having a chromatic dispersion of +1.0 ps/nm/km or more in a 1460 nm wavelength band, a dispersion slope of 0.04 ps/nm2/km or less in a 1550 nm wavelength band, and a cutoff wavelength of 1450 nm or less, comprises a relation of an RDS, which is a value of the dispersion slope to the chromatic dispersion, to a wavelength &lgr; is −1.67×10−5&lgr;+0.0300≧RDS(&lgr;)≧−1.67×10−5&lgr;+0.0285.

Abstract: In order to provide a dispersion-compensating optical fiber able to be applied over a broad wavelength band, having a large effective area, and as a result, suppressing the occurrence of non-linear effects, the present invention comprises a dispersion-compensating optical fiber that compensates chromatic dispersion of a 1.3 &mgr;m single-mode optical fiber over the entire wavelength range of 1.53-1.63 &mgr;m characterized in that, chromatic dispersion at a wavelength of 1.55 &mgr;m is −50 ps/nm/km or less, the dispersion slope is negative over the entire wavelength range of 1.53-1.63 &mgr;m, a cutoff wavelength is provided at which there is substantially single-mode propagation, bending loss is 30 dB/m or less, effective area is 20 &mgr;m2 or more, and the absolute value of chromatic dispersion during compensation of the chromatic dispersion of a 1.3 &mgr;m single-mode optical fiber serving as the target of compensation is 0.5 ps/nm/km or less.

Abstract: There is disclosed a metal particle-dispersed composite oxide comprising a matrix material containing a composite oxide comprising a non-reducible metal oxide and an easily reducible metal oxide, the composite oxide containing 0.01 to 0.25 mol % of at least one additive metal selected from Al, Sc, Cr, B, Fe, Ga, In, Lu, Nb and Si, surface metal particles precipitated on an outer surface of the matrix material containing the composite oxide, and inner metal particles precipitated on an inner surface of the matrix material containing the composite oxide.

Abstract: A manufacturing method and apparatus for manufacturing a coated optical fiber which has a superior surface smoothness of a resin coating and which can be coated with a colored ink with high coating performance. In the method including the steps of making a coated optical fiber by forming an outer coating layer around a bare optical fiber; and winding the coated optical fiber via pulleys by a take-up, the surface roughness of each solid body which the outer layer of the running coated optical fiber contacts is 0.8 &mgr;m or less. When the temperature of the outer coating layer is a room temperature or the Young's modulus of the outer coating layer is higher than 500 MPa, the surface roughness of each solid body, which the outer layer of the coated optical fiber contacts during drawing or rewinding, is 1.2 &mgr;m or less.

Abstract: In order to provide a dispersion-compensating optical fiber able to be applied over a broad wavelength band, having a large effective area, and as a result, suppressing the occurrence of non-linear effects, the present invention comprises a dispersion-compensating optical fiber that compensates chromatic dispersion of a 1.3 &mgr;m single-mode optical fiber over the entire wavelength range of 1.53-1.63 &mgr;m characterized in that, chromatic dispersion at a wavelength of 1.55 &mgr;m is −50 ps/nm/km or less, the dispersion slope is negative over the entire wavelength range of 1.53-1.63 &mgr;m, a cutoff wavelength is provided at which there is substantially single-mode propagation, bending loss is 30 dB/m or less, effective area is 20 &mgr;m2 or more, and the absolute value of chromatic dispersion during compensation of the chromatic dispersion of a 1.3 &mgr;m single-mode optical fiber serving as the target of compensation is 0.5 ps/nm/km or less.

Abstract: A multi-tube burner is provided which includes a cylindrical outermost nozzle and at least one cylindrical inner nozzle provided coaxially with the outermost nozzle to form annular jet openings for gases used to manufacture a glass preform. The angle between a center axis of an outer circumference of the outermost nozzle and a distal end portion of each of the inner nozzles is 90°± not more than 3°. Furthermore, the distance between the center axis of the outer circumference of the outermost nozzle and each of center axes of inner circumferences and outer circumferences of the inner nozzles is not more than 0.20 mm.

Abstract: Marigold oleoresin having a low viscosity and a high lutein content which can be filled in soft capsules can be obtained according to the method of the present invention, which is characterized by combining a step of subjecting oleoresin to supercritical fluid extraction and a step of dissolving oleoresin in a ketone solvent, cooling the solution and removing the ingredient which precipitated in solution.

Abstract: A solid-state imaging device includes a plurality of sensor portions, and a vertical shift register corresponding to each of a series of sensor portions. A transfer electrode of the vertical shift register is formed of a first electrode and a second electrode which are repeatedly provided corresponding to the respective series of sensor portions and also formed continuously between the sensor portions adjacent to each other in the vertical direction. A signal charge is read out from each of the sensor portions through a portion below a read gate portion of the first electrode between sensor portions a located in the vertical direction.

Abstract: Under condition that a non-circularity ratio is 5% or lower and a thermal expansion coefficient of a glass which forms the core is &agr;1 and a thermal expansion of a glass which forms the cladding is &agr;2, the difference of coefficients is controlled such that a formula −2.5×10−7/° C.≦&agr;1−&agr;2≦1.0×10−7/° C. is satisfied so as to maintain a polarization mode dispersion to be 0.03 ps/km0.5 or lower. The difference of coefficients is further controlled such that a formula −1.5×10−7/° C.≦&agr;1−&agr;2≦0/° C. is satisfied so as to maintain a polarization mode dispersion to be 0.015 ps/km0.5 or lower. By doing this, birefringence is reduced by adjusting the thermal expansion coefficient in a core and a cladding; thus providing an optical fiber, and an optical transmission path using the optical fiber, having preferable PMD for high speed transmission.