Abstract: A buffered optical fiber having an excellent pistoning characteristic compared with a conventional one and a manufacturing method thereof are provided. The buffered optical fiber of the present invention is composed of an optical fiber with a primary coating layer and a secondary coating layer provided on a circumference of a glass optical fiber and a tertiary coating layer having thermoplastic polyester elastomer as the main ingredient provided on a circumference of the optical fiber and is characterized in that an outer diameter of the primary coating layer is 180 to 200 ?m, an outer diameter of the secondary coating layer is 350 to 450 ?m and the product of a thickness of the secondary coating layer of the optical fiber and a force of pulling out the glass optical fiber from the optical fiber is 720 N/mm·?m or more.

Abstract: A buffered optical fiber having an excellent pistoning characteristic compared with a conventional one and a manufacturing method thereof are provided. The buffered optical fiber of the present invention is composed of an optical fiber with a primary coating layer and a secondary coating layer provided on a circumference of a glass optical fiber and a tertiary coating layer having thermoplastic polyester elastomer as the main ingredient provided on a circumference of the optical fiber and is characterized in that an outer diameter of the primary coating layer is 180 to 200 ?m, an outer diameter of the secondary coating layer is 350 to 450 ?m and the product of a thickness of the secondary coating layer of the optical fiber and a force of pulling out the glass optical fiber from the optical fiber is 720 N/mm·?m or more.

Abstract: A guide hole guides a primary-coated optical fiber to a tubular inlet hole. An inner diameter of the guide hole is larger than that of the tubular inlet hole. An inner diameter of the tubular inlet hole is in a range from 1.5 times to 2.0 times that of the primary-coated optical fiber. A length of the tubular inlet hole is in a range from 1.0 mm to 2.0 mm. A depth of the guide hole is in a range from 2.0 mm 9.0 mm. A relation B?A is satisfied, with B equal to or larger than 7.0 mm, where A is an inner diameter of a leading edge of the guide hole continued to a trailing edge of the tubular inlet hole, and B is an inner diameter of a trailing edge of the guide hole.

Abstract: A guide hole guides a primary-coated optical fiber to a tubular inlet hole. An inner diameter of the guide hole is larger than that of the tubular inlet hole. An inner diameter of the tubular inlet hole is in a range from 1.5 times to 2.0 times that of the primary-coated optical fiber. A length of the tubular inlet hole is in a range from 1.0 mm to 2.0 mm. A depth of the guide hole is in a range from 2.0 mm 9.0 mm. A relation B?A is satisfied, with B equal to or larger than 7.0 mm, where A is an inner diameter of a leading edge of the guide hole continued to a trailing edge of the tubular inlet hole, and B is an inner diameter of a trailing edge of the guide hole.

Abstract: Two or more optical waveguides are placed in a treatment vessel. The optical waveguides in the treatment vessel are treated with a chemical substance containing at least one of deuterium, hydrogen, and a compound thereof. The treating includes causing molecules of the chemical substance to diffuse into the optical waveguides, causing the molecules of the chemical substance that have diffused into the optical waveguides to react with structural defects that exist in a portion, through which light propagates, of the optical waveguides, and removing from the optical waveguides molecules of the chemical substance that do not react with the structural defect.

Abstract: The dynamic gain equalizer for flattening a gain profile of an optical amplifier includes: an optical waveguide circuit having multistage optical couplers, demultiplexing and multiplexing, each formed by connecting optical couplers arranged at a plurality of stages; and optical connecting circuits including optical phase shifters each capable of changing a phase of propagating light and optical delay lines each for adding a predetermined delay time to the propagating light, said dynamic gain equalizer in which at least one of the optical couplers in the two multistage optical couplers are provided with variable optical amplitude means, respectively, and each of the multistage optical couplers are formed asymmetrically with respect to an extension of a line which connects a center arranged position of optical outputting ends of the demultiplexing multistage optical coupler with a center arranged position of optical inputting ends of the multiplexing multistage optical coupler.

Abstract: A dispersion compensator includes at least one first optical waveguide, a first slab waveguide, an arrayed waveguide connected to the at least one first optical waveguide via the first slab waveguide, a second slab waveguide, at least one second optical waveguide connected to the arrayed waveguide via the second slab waveguide, and a phase distribution provider configured to provide a phase distribution to the arrayed waveguide.

Abstract: A dispersion compensator includes at least one first optical waveguide, a first slab waveguide, an arrayed waveguide connected to the at least one first optical waveguide via the first slab waveguide, a second slab waveguide, at least one second optical waveguide connected to the arrayed waveguide via the second slab waveguide, and a phase distribution provider configured to provide a phase distribution to the arrayed waveguide.

Abstract: A dispersion compensator includes at least one first optical waveguide, a first slab waveguide, an arrayed waveguide connected to the at least one first optical waveguide via the first slab waveguide, a second slab waveguide, at least one second optical waveguide connected to the arrayed waveguide via the second slab waveguide, and a phase distribution provider configured to provide a phase distribution to the arrayed waveguide.

Abstract: The present invention provides a dynamic gain equalizer for flattening a gain profile of an optical amplifier.

Abstract: An arrayed waveguide grating optical multiplexer/demultiplexer includes an arrayed waveguide connected to at least one first optical waveguide via a first slab waveguide, a plurality of second optical waveguides connected to the arrayed waveguide via a second slab waveguide. At least one expanding width waveguide has a first end portion and a second end portion having a second width larger than a first width of the first end portion. Each first end portion is connected to each first optical waveguide. The second end portion is connected to the first slab waveguide. The first width of the first end portion is larger than a first optical waveguide width of the at least one first optical waveguide. The first width of the first end portion satisfies a single mode condition. A width of the expanding width waveguide increases from the first end portion toward the second end portion.

Abstract: Two or more optical waveguides are placed in a treatment vessel. The optical waveguides in the treatment vessel are treated with a chemical substance containing at least one of deuterium, hydrogen, and a compound thereof. The treating includes causing molecules of the chemical substance to diffuse into the optical waveguides, causing the molecules of the chemical substance that have diffused into the optical waveguides to react with structural defects that exist in a portion, through which light propagates, of the optical waveguides, and removing from the optical waveguides molecules of the chemical substance that do not react with the structural defect.

Abstract: An arrayed waveguide grating type optical multiplexer/demultiplexer in which the 1 dB band width is large, the ripple is small, and the degradation of the adjacent crosstalk can be controlled. A waveguide forming portion is formed on a substrate. The waveguide forming portion includes an optical input waveguides, a first slab waveguide, an arrayed waveguide including a plurality of channel waveguides arranged side by side and which have different lengths with the differences preset, a second slab waveguide, and a plurality of optical output waveguides arranged side by side, all of the components being connected in the order stated. A single mode straight waveguide narrower than the optical input waveguides is provided at the output end of at least one or more optical input waveguides. A multi-mode trapezoidal waveguide whose width increases toward the arrayed waveguide is provided at the output end of the straight waveguide.

Abstract: An optical fiber module of the invention is a small-sized optical fiber module with small electric power consumption in which the characteristics are hardly deteriorated in association with environmental changes. The optical fiber module has a package, an optical component housed inside the package, and optical component holding parts disposed between the optical component and the package for holding the optical component. The configuration of holding the optical component by the optical component holding parts has a configuration of reducing heat conduction for reducing the heat conduction between the optical component and the package. The configuration of reducing heat conduction is such that the optical component holding parts hold the optical component in line contact.

Abstract: An optical waveguide circuit device strong in impact strength in dropping, etc. is provided. A waveguide pattern is formed on a silicon substrate in this optical waveguide circuit device. For example, this waveguide pattern has an optical input waveguide, a first slab waveguide, an arrayed waveguide including a plurality of channel waveguides having lengths different from each other and arranged side by side, a second slab waveguide, and a plurality of optical output waveguides arranged side by side. The first slab waveguide is separated on a cross separating face crossing an optical path passing the first slab waveguide. A temperature dependence in light transmission central wavelength of an arrayed waveguide grating is reduced by sliding and moving a separating slab waveguide side by a slide moving member along the separating face depending on temperature.

Abstract: At least one of two slab waveguides constituting an arrayed waveguide grating is cut and separated together with a substrate on a cross separating face. A slide moving member is arranged over a waveguide forming area formed on the substrate including the separating slab waveguide and a waveguide forming area formed on the substrate including the separating slab waveguide. Temperature dependence of the center wavelength of the arrayed waveguide grating is reduced by slide-moving the separating slab waveguide by the slide moving member along the cross separating face dependently on temperature. The shift of an initial center wavelength is corrected by plastically deforming the slide moving member so that the initial center wavelength is conformed to a grid wavelength.

Abstract: An arrayed waveguide grating optical multiplexer/demultiplexer is configured to multiplex a plurality of lights having different wavelengths with a designed wavelength spacing and to demultiplex a light into a plurality of lights having different wavelengths with the designed wavelength spacing. The designed wavelength spacing is determined such that a value which is obtained by multiplying the designed wavelength spacing by an integer which is at least two is substantially equal to an actual wavelength spacing of lights which are input to or output from the multiplexer/demultiplexer.

Abstract: An optical multiplexer/demultiplexer has a plurality of Mach-Zehnder optical interferometer multiplexing/demultiplexing circuits connected in plural stages, at least one of the plurality of Mach-Zehnder optical interferometer multiplexing/demultiplexing circuits including a first optical waveguide, a second optical waveguide disposed along the first optical waveguide, a first directional coupling portion that connects a first part of the first optical waveguide to a first part of the second optical waveguide, and a second directional coupling portion that connects a second part of the first optical waveguide to a second part of the second optical waveguide.

Abstract: An optical fiber module is formed by storing an optical component and a connection portion of this optical component and an optical fiber into a package. The optical fiber module has the package, the optical component unfixedly stored into the package, and the optical fiber in which one end side of the optical fiber is connected to the optical component and the other end side is pulled out of the package to the package exterior. An optical fiber anchor member is arranged in the package in an extraction preventing state in an optical fiber pulling-out area of the package. The optical fiber is fixed to the optical fiber anchor member. The optical fiber anchor member and the package are set to be relatively moved in the optical fiber longitudinal direction.

Abstract: An arrayed waveguide grating optical multiplexer/demultiplexer includes an arrayed waveguide having a plurality of channel waveguides which includes a shortest channel waveguide having a shortest length. Each channel waveguide includes a curved portion provided between first and second connection portions. The shortest channel waveguide has a radius (R1) of curvature of the curved portion and an angle (&thgr;1) which is a half of a central angle of the curved portion. The radius (R1) of curvature and the angle (&thgr;1) are determined such that a product (R1×&thgr;1) is a value within a range which includes a minimum value of the product (R1×&thgr;1) and in which all of the plurality of channel waveguides are drawn.