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. Tensile stress applied from the exterior to the optical fiber and the influence of thermal expansion and contraction of the package are restrained by this relative movement.

Abstract: A dispersion compensator with Bragg gratings which have a dispersion compensating function and are formed on output waveguides of an arrayed waveguide grating, and a dispersion-compensating module employing the dispersion compensator.

Abstract: A planar lightwave circuit module includes a plate provided on a substrate. An end array surface of an optical fiber array is connected to an end substrate surface of the substrate and an end plate surface of the plate such that at least one optical fiber of the optical fiber array is connected to at least one optical waveguide formed on an upper substrate surface of the substrate and such that a bottom substrate surface of the substrate and a bottom array surface of the optical fiber array are substantially on a first plane and/or an upper plate surface of the plate and an upper array surface of the optical fiber array are substantially on a second plane.

Abstract: A method for compensating a center wavelength of optical transmission of a planar lightwave circuit includes heating the planar lightwave circuit from a first set temperature to a second set temperature. The first set temperature is at least approximately a room temperature and at most approximately 500° C. The second set temperature is at least approximately 500° C. and at most approximately 900° C. The planar lightwave circuit is maintained at the second set temperature for a predetermined retention time. The planar lightwave circuit is cooled from the second set temperature to a third set temperature. The third set temperature is at least approximately a room temperature and at most approximately 500° C.

Abstract: An arrayed waveguide grating optical multiplexer/demultiplexer includes first and second slab waveguides. At least one of the first and a second slab waveguides includes first and second portions which are separated along an intersecting face intersecting an optical path in the first or second slab waveguides. A slider is fixed at a temperature shifted from a predetermined temperature to compensate a center wavelength difference between a target center wavelength of optical transmission of the arrayed waveguide grating optical multiplexer/demultiplexer at the predetermined temperature and the measured center wavelength of optical transmission of the arrayed waveguide grating optical multiplexer/demultiplexer at the predetermined temperature. The slider is configured to cause a relative motion between the first and second portions along the intersecting face according to a temperature change.

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 (8). A slide moving member (17) is arranged over a waveguide forming area formed on the substrate including the separating slab waveguide (3a) and a waveguide forming area formed on the substrate including the separating slab waveguide (3b). Temperature dependence of the center wavelength of the arrayed waveguide grating is reduced by slide-moving the separating slab waveguide (3a) by the slide moving member (17) along the cross separating face (8) dependently on temperature. The shift of an initial center wavelength is corrected by plastically deforming the slide moving member (17) so that the initial center wavelength is conformed to a grid wavelength.

Abstract: While an arrangement is provided in which at least one stage of a Mach-Zehnder optical interferometer optical multiplexing/demultiplexing circuit (8) is connected, at least two optical output waveguides (6) are provided at a final stage. Each of the optical multiplexing/demultiplexing circuits contains a first optical waveguide (3); a second optical waveguide (4); and a plurality of directional coupling portions (1, 2) formed in such a manner that the first optical waveguide (3) is provided in proximity to the second optical waveguide (4). Optical transmission filters (7) are provided in the respective optical output waveguides (6) of the final stage, while the optical transmission filters (7) transmit therethrough light having setting wavelengths which are determined in correspondence with the respective optical output waveguide (6).

Abstract: An optical multiplexer/demultiplexer including an arrayed waveguide grating having a plurality of waveguides and formed at its both end with an input-side slab waveguide and an output-side slab waveguide. A reference input waveguide and correction input waveguides are provided on the input end face of the input-side slab waveguide and a plurality of output waveguides are connected to the output end face of the output-side slab waveguide. The correction input waveguide has an output end face thereof placed apart by a distance from the input end face of the input-side slab waveguide in the lengthwise direction of the slab waveguide and has an acute angle to a plane perpendicular to the optical axis of this waveguide, thus permitting an optical signal to be input at a position apart from a light-incident position for the reference input waveguide by a distance shorter than a waveguide disposition interval, thereby optimally correcting a deviation of the center wavelength of the optical signal.

Abstract: The present invention relates to an optical wavelength multiplexing and dividing device of an array waveguide type diffraction lattice, which is capable of separating and picking up wavelength-multiplexed signals of various wavelengths, which are used in optical transmissions. An input side slab waveguide (3), a plurality of juxtaposed array waveguides (4), an output side slab waveguide (5) and a plurality of optical output waveguides (6) are connected, in order, to the outgoing sides of a plurality of optical input waveguides (2), thereby forming a waveguide pattern. The array waveguides (4) are formed so as to have lengths different from each other to cause the phases of individual lights to be deviated after propagating through the respective array type waveguides (4), wherein different lights as per wavelength are condensed at the incident ends (7) of optical output waveguides 6 by passing through the output side slab waveguides (5) and are outputted through the optical output waveguides (6).

Abstract: An arrayed waveguide grating type optical multiplexer/demultiplexer including an arrayed waveguide grating having a plurality of channel waveguides. Concave end faces of input-side and output-side slab waveguides are connected to opposite ends of the diffraction grating. At least one input waveguide and at least one output waveguide are connected to the other concave end faces of the input-side and output-side slab waveguides, respectively. The focal length of the output-side slab waveguide end face is longer than the focal length of the input-side slab waveguide end face. The optical multiplexer/demultiplexer has a sufficiently flat wavelength-dependent spectrum response in passing channel spacings, and helps construct an optical wavelength multiple communication system having a good signal-to-noise ratio.

Abstract: An optical multiplexer/demultiplexer 1 having a plurality of first waveguides 3, a first slab waveguide 4, an arrayed waveguide grating 5 having a plurality of waveguides, a second slab waveguide 6 and a plurality of second waveguides 7, the individual waveguides being connected in the above order. The ratio of a distance between the plurality of first waveguides 3 at a connecting portion with the first slab waveguide 4 to a distance between the plurality of second waveguides 7 at a connecting portion with the second slab waveguide 6 differs from a ratio of a focal length of the first slab waveguide 4 to a focal length of the second slab waveguide 6.

Abstract: A plurality of pumping light sources (1) which generate pumping light having wavelengths different from each other are connected to respective input ports of an optical multiplexer via optical reflectors (3). The respective pumping light is stabilized by optical reflectors with respect to the oscillating wavelengths, and is multiplexed by an optical multiplexer (4). The multiplexed pumping light is multiplexed to signal light passing through an optical fiber (6) for amplification.

Abstract: The permeation of the moisture into a case made of metal is roughly perfectly suppressed, and the optical communications of high quality are made possible by the operation of component(s) accommodated in the case. A plurality of through holes through which the outside of the case and a component accommodating portion communicate with each other are provided in the metallic case including a body having the component accommodating portion, and a lid. Fixed components in which an optical fiber ribbon and an optical fiber(s) are respectively sandwiched between associated metallic substrates and associated optical fiber fixing plates to be fixed by solder are fitted into the respective through holes to be hermetically sealed and fixed to the metallic case.

Abstract: A dispersion compensator with Bragg gratings which have a dispersion compensating function and are formed on output waveguides of an arrayed waveguide grating, and a dispersion-compensating module employing the dispersion compensator.

Abstract: A linear random N-substituted acrylamide copolymer comprising 65 to 99% by mole of ethylene units, 1 to 15% by mole of acrylate units and 1 to 35% by mole of acrylamide units, the copolymer having a weight average molecular weight of 1000 to 50000, and an aqueous composition, a resin film, a laminate, recording paper and a foamed article comprising the N-substituted acrylamide copolymer, respectively. The N-substituted acrylamide copolymer is excellent in antistatic ability for thermoplastic resins and does not lower physical properties such as transparency and elongation of films and articles which are formed from a thermoplastic resin. Moreover, the N-substituted acrylamide copolymer is excellent in anti-blocking ability so that the copolymer can be suitably used for various uses.

Abstract: A molded laminated article is made from (a) a composite comprising a crosslinked polyolefin resin foam having an average gel proportion of 10 to 75% and an average expansion ratio of 5 to 40, in which the average expansion ratio in a portion having a thickness of 0.5 mm on the side of one surface of the foam is larger than the average expansion ratio in a portion having a thickness of 0.5 mm on the side of the other surface thereof and the difference between said average expansion ratios is from 2 to 20, and a skin material bonded to the surface having the larger average expansion ratio, and (b) a thermoplastic resin as a skeleton material, as follows.

Abstract: A method is provided for producing high purity electrolytic copper useful, for example, to make a copper wire for use in sound or image reproducing systems, such as audio, video and television systems, etc. The copper wire consists of high purity copper in which silver and sulfur contents are both not more than 0.5 ppm and preferably has a crystal grain size not less than 0.02 mm and is unidirectionally solidified or is a single crystal. Such a copper wire is manufactured by continuously casting electrodeposited copper which has been obtained by refining by re-electrolysis of electrolytic copper, using a specially arranged casting apparatus having a mold projecting to an electrolytic bath.

Abstract: An improved FMX sterophonic broadcast receiver provided with countermeasures against transient noises, which includes a level detection circuit for detecting level of a detected stereo difference signal, and a level control circuit for controlling level of an expanded stereo difference signal according to an output signal of the level detection circuit. By the above arrangement of the present invention, since it is so arranged to cause the level control circuit to function when the degree of modulation becomes large so as to control the level of the stereo difference signal to be low, a level difference is produced between the stereo sum signal and the stereo difference signal for deterioration of the stereo separation degree upon matrixing at a matrix circuit for reduction of noises accordingly.

Abstract: An FMX stereophonic receiver receives an FMX stereophonic broadcast signal which includes a stereo sum signal, an uncompressed stereo difference signal, and a compressed stereo difference signal which is formed by modulating the uncompressed stereo difference signal by a quadrature modulation and being compressed.

Abstract: An FM/FMX stereophonic receiver is capable of receiving an FM or an FMX stereophonic broadcast signal. The FM stereophonic broadcast signal includes a stereo sum signal and stereo difference signal, whereas the FMX stereophonic broadcast signal further includes a compressed stereo difference signal and an FMX ID signal indicating the FMX stereophonic broadcast signal. The FM/FMX stereophonic receiver has a stereo demodulator for receiving said broadcast signal and for producing left and right stereo signals, a detector for detecting the field strength of the receiving signal, and a noise reducer, which may be a circuit for changing the mode from stereophonic mode to monaural mode or a high cut circuit for attenuating the signals of high frequency region, for reducing noise signals contained in the left and right stereo signals.