Abstract: According to an aspect of an embodiment, an apparatus includes an optical branching unit for branching an input signal light in four directions, a polarization component extraction unit extracting four polarization components having mutually different polarization parameters from lights branched in four directions by the optical branching unit, and a determination unit determining input/non-input of the signal light based on the four polarization components extracted by the polarization component extraction unit.

Abstract: A communication system including: a transmission apparatus configured to modulate a first light by using a first signal to be transferred and a second signal having a frequency different from a frequency of the first signal so as to generate a first optical signal, modulate a second light by using a third signal to be transferred and a fourth signal having a frequency different from a frequency of the third signal so as to generate a second optical signal, polarization-multiplex the first optical signal and the second optical signal, and transmit a polarization-multiplexed optical signal in which the first optical signal and the second optical signal are polarization-multiplexed, each of the first light and the second light being polarized; and a measuring apparatus configured to measure powers of the second signal and the fourth signal which are included in the polarization-multiplexed optical signal transmitted from the transmission apparatus.

Abstract: A phase shift unit provides a prescribed phase difference (?/2, for example) between a pair of optical signals transmitted via a pair of arms constituting a data modulation unit. A low-frequency signal f0 is superimposed on one of the optical signals. A signal of which phase is shifted by ?/2 from the low-frequency signal f0 is superimposed on the other optical signal. A pair of the optical signals is coupled, and a part of which is converted into an electrical signal by a photodiode. 2f0 component contained in the electrical signal is extracted. Bias voltage provided to the phase shift unit is controlled by feedback control so that the 2f0 component becomes the minimum.

Abstract: In a polarization multiplexed optical transmitting and receiving apparatus, output light from a light source section of a transmission unit is separated in a polarization separating section, and then modulated in first and second modulation sections, and the modulated lights are synthesized in a polarization synthesizing section, and transmitted to an optical transmission line. Then the polarization multiplexed light propagated through the optical transmission line is demodulated in a reception section of a reception unit, and together with this, transmission characteristic information of the reception light is transferred to the transmission unit. The transmission unit that receives the transmission characteristics information controls a delay section that adjusts a delay amount of relative phases of drive signals of the modulation sections, so that the transmission characteristics of the polarization multiplexed light are within an allowable range.

Abstract: According to an aspect of an embodiment, a signal detector device includes a first monitor unit, a second monitor unit, and a discrimination unit, wherein the discriminator unit discriminates whether an inputted light includes a signal light on the bases of the first monitor unit for monitoring an intensity of the inputted light and the second monitor unit for monitoring an alternating current component intensity of the inputted light.

Abstract: A dispersion compensating apparatus includes a tunable dispersion compensator that dispersion-compensates an optical signal using a group delay property that is asymmetrical in bands outside an effective band; a set device that sets a dispersion compensation amount in the tunable dispersion compensator; and a shifter that shifts a central frequency of the effective band of the tunable dispersion compensator, based on the dispersion compensation amount set by the set device.

Abstract: According to an aspect of an embodiment, a signal detector device includes a first monitor unit, a second monitor unit, and a discriminator unit. The discriminator unit discriminates whether an inputted light includes a signal light on the bases of the first monitor unit for monitoring an intensity of the inputted light and the second monitor unit for monitoring an alternating current component intensity of the inputted light.

Abstract: A phase shift unit provides a prescribed phase difference (?/2, for example) between a pair of optical signals transmitted via a pair of arms constituting a data modulation unit. A low-frequency signal f0 is superimposed on one of the optical signals. A signal of which phase is shifted by ?/2 from the low-frequency signal f0 is superimposed on the other optical signal. A pair of the optical signals is coupled, and a part of which is converted into an electrical signal by a photodiode. 2f0 component contained in the electrical signal is extracted. Bias voltage provided to the phase shift unit is controlled by feedback control so that the 2f0 component becomes the minimum.

Abstract: In an optical transmitter of the invention, continuous light from a light source is a (CS)RZ-D(Q)PSK modulated by two optical modulators connected in series, and a part of the optical signal output from a post-stage optical modulator is branched by an output monitor section, and the power of a preset frequency component, excluding a frequency component corresponding to a baud rate, included in an electrical spectrum acquired by photoelectrically converting the branched beams is measured. The relative phase of drive signals applied to the optical modulators is then feed-back controlled so that the power becomes a minimum. As a result, a delay shift due to a temperature change or the like between drive signals applied to respective optical modulators, can be reliably compensated.

Abstract: A thermal transfer image-receiving sheet which comprises a substrate sheet and a receiving layer comprising a polyester resin provided on at least one surface of the substrate sheet, wherein the receiving layer is a layer formed by applying a coating solution comprising 1 to 3% by weight of a modified silicone oil (I) modified with both groups of an aminoalkyl group and a polyalkylene ether group, and 0.1 to 4.0% by weight of a curing agent based on 100 parts by weight of the polyester resin, and drying the solution, 0.2 to 3% by weight of a polyether-modified silicone oil (II) and/or phenol-modified silicone oil (III) being contained in the coating solution, if desired.

Abstract: A main object of the present invention is to provide a receptor layer forming resin which makes it possible to obtain a receptor layer for a thermal transfer image receptor sheet having excellent dyeing property. The present invention achieves the above object by providing a receptor layer forming polyurethane resin for a thermal transfer image receptor sheet obtained by copolymerizing: a high molecular weight polyol having a number average molecular weight of 1000 or higher (A); an organic isocyanate (B); and according to need, a polyol compound having a number average molecular weight of 500 or lower (C), wherein the receptor layer forming polyurethane resin for a thermal transfer image receptor sheet meets the following requirements (1) to (4): (1) the resin has at least two glass transition temperatures; (2) at least one of the glass transition temperatures is between ?200 to 0° C., and at least one is between 20 to 100° C.

Abstract: The polarization multiplexed light transmitter takes out a part of a polarization multiplexed light to be transmitted as a monitor light; makes orthogonal polarization components contained in the monitor light to interfere with each other, to generate a polarization interfering light; converts the polarization interfering light into an electric signal; measures the power of an alternate current component contained in the electric signal after eliminating a direct current component thereof; and feedback controls delay amount varying sections so that an inter-polarized channel delay time judged based on a change in the measured power reaches a predetermined value. Thus, the delay time between the orthogonal polarization components in the polarization multiplexed light can be varied flexibly at a high speed with a simple configuration, and thus, it becomes possible to suppress transmission characteristics degradation of the polarization multiplexed light due to a change in system state.

Abstract: The present invention provides a control apparatus including: an output monitor which monitors polarization-multiplexed output light output from a polarization multiplexing light modulator which modulates light of two systems independent of each other, polarization-multiplexes light signals of the two systems subjected to the light modulation, and outputs the polarization-multiplexed light signals; and a control unit which controls a delay time difference at a stage where the light signals of the two systems forming the polarization multiplexing light modulator are polarization-multiplexed based on a monitor result of the output monitor. The control apparatus controls a delay time difference between polarization channels easily or surely.

Abstract: An optical network system enabling confirmation of connection and tracking of wavelength paths at a high speed and a low cost without introducing any special hardware by having a wavelength path monitoring unit in an NMS give temporary change of optical power through a change generating unit to an optical signal S from an optical transmitting/receiving node, by having a change detecting unit confirm that this change of optical power has propagated through an optical transmission line and appeared at each node on the way, and confirming connections and monitoring the wavelength path while confirming the presence of the change.

Abstract: Disclosed is a thermal transfer sheet that can meet demands for increased printing speed in thermal transfer, higher density of thermally transferred images, and higher quality. The thermal transfer sheet comprises a substrate and an adhesive layer and a dye layer provided in that order on one side of the substrate, wherein the adhesive layer comprises a polyvinylpyrrolidone resin and a composition for suppressing hygroscopic properties of the polyvinylpyrrolidone resin.

Abstract: Disclosed is a thermal transfer sheet that can meet demands for increased printing speed in thermal transfer, higher density of thermally transferred images, and higher quality. The thermal transfer sheet comprises a substrate and an adhesive layer and a dye layer provided in that order on one side of the substrate, wherein the adhesive layer comprises a polyvinylpyrrolidone resin and a composition for suppressing hygroscopic properties of the polyvinylpyrrolidone resin.

Abstract: In a polarization multiplexed optical transmitting and receiving apparatus, output light from a light source section of a transmission unit is separated in a polarization separating section, and then modulated in first and second modulation sections, and the modulated lights are synthesized in a polarization synthesizing section, and transmitted to an optical transmission line. Then the polarization multiplexed light propagated through the optical transmission line is demodulated in a reception section of a reception unit, and together with this, transmission characteristic information of the reception light is transferred to the transmission unit. The transmission unit that receives the transmission characteristics information controls a delay section that adjusts a delay amount of relative phases of drive signals of the modulation sections, so that the transmission characteristics of the polarization multiplexed light are within an allowable range.

Abstract: A polarization scrambler has a polarization state rotating unit rotating the polarization state of a signal light, and a rotation speed controlling unit controlling the rotation speed of the polarization state in the polarization state rotating unit on the basis of the speed and scheme of modulation of the signal light, and the value of polarization mode dispersion of a transmission path on which the signal light is to be transmitted. Degradation of the transmission quality due to PMD is more mitigated than the known techniques.

Abstract: According to an aspect of an embodiment, an apparatus includes an optical branching unit for branching an input signal light in four directions, a polarization component extraction unit extracting four polarization components having mutually different polarization parameters from lights branched in four directions by the optical branching unit, and a determination unit determining input/non-input of the signal light based on the four polarization components extracted by the polarization component extraction unit.

Abstract: A thermal transfer sheet that can meet demands for increased printing speed in thermal transfer, increased density of thermally transferred images, and higher quality and, at the same time, particularly can suppress fusing to image receiving sheets and abnormal transfer. The thermal transfer sheet includes a base material, a heat resistant slip layer provided on one side of the base material, and an adhesive layer and a dye layer provided in that order on the other side of the base material, wherein the adhesive layer includes a specific polyvinylpyrrolidone resin.