Abstract: At least one of a first device, a second device, and a relay device compensates for wavelength dispersion in a first optical wavelength path. The first or second device changes a wavelength dispersion compensation amount at the first or second device so that wavelength dispersion in a second optical wavelength path is compensated. The relay device changes a wavelength dispersion compensation amount at the relay device so that a total amount of wavelength dispersion of the signal light compensated in the first optical wavelength path does not change substantially with the change in the wavelength dispersion compensation amount at the first or second device. The first optical wavelength path is switched to the second optical wavelength path after the wavelength dispersion compensation amount at the first or second device is changed to a value that can compensate for the wavelength dispersion in the second optical wavelength path.

Abstract: A clock signal from a single reference clock is frequency converted, and the frequency-converted signal is input to an equal-interval-optical-frequency-comb generator and a modulator of an optical modulator. By varying the electric frequency of the clock signal input to the equal-interval-optical-frequency-comb generator, frequency intervals of a frequency comb to be generated can be varied, while by selectively employing a particular optical frequency from among the continuous light beams of the generated frequency comb, a frequency comb having unequal intervals can be generated. It is also possible to vary the modulation rate by varying the clock frequency of a driving signal to be input to the optical modulator. By using a clock signal of a single reference clock, the frequency intervals of the frequency comb and the variation of the modulation rate synchronize with each other.

Abstract: A transmission control device includes a subcarrier selector configured to select one or more subcarriers for transmitting an error correction code for correcting data, from a plurality of subcarriers having different transmission capacities, each of the plurality of subcarriers used for transmitting either of the data and the error correction code, in accordance with an amount of data of the error correction code and transmission capacities respectively assigned to the plurality of subcarriers.

Abstract: A banknote handling apparatus that performs a depositing handling or a depositing/dispensing handling by transporting banknotes along a transport path includes a recognizing unit that recognizes an inserted banknotes; a deposit acceptability judging unit that determines, based on a recognition result obtained by the recognizing unit, whether the banknotes is acceptable for deposit; a reject reason identifying unit that identifies a reject reason of rejected banknotes that is determined to be unacceptable for deposit by the deposit acceptability judging unit; and a dispensing handling unit that sorts and dispenses the rejected banknotes based on the reject cause identified by the reject cause identifying unit.

Abstract: A polarization fluctuation compensation device, when WDM light received by, for example, an optical reception device includes a polarization scrambled optical signal and a non-polarization scrambled optical signal, collects information related to whether optical signals having respective wavelengths are polarization scrambled, obtains a target value of control parameters which are different from each other, according to the speed of polarization fluctuations in the non-polarization scrambled optical signal based on the collected information, and performs reception processing of the non-polarization scrambled optical signal by using a control parameter set as the target value. As a result, an influence of fast polarization fluctuations generated resulting from an interaction between optical signals having respective wavelengths can be reliably compensated for, thereby enabling to realize excellent reception characteristics.

Abstract: An optical signal transmitting apparatus is disposed in an optical frequency division multiplex transmission system that includes plural nodes that are in an optical transmission path and respectively use a unique frequency to frequency-multiplex information with a carrier wave to transmit the information to an optical signal receiving apparatus in the optical transmission path. The optical signal transmitting apparatus outputs the carrier wave and includes a transmitting unit into which information to be delivered to the nodes is input, the transmitting unit transmitting the information using a frequency that does not overlap the unique frequencies used by the nodes; and a multiplexing unit that frequency-multiplexes output of the transmitting unit and the carrier wave, and sends the frequency-multiplexed output to the optical transmission path.

Abstract: A transmitting apparatus is used in an electrical frequency division multiplex transmission system including nodes that are on an optical transmission path and that respectively frequency-multiplex a sub-carrier of a unique frequency and a carrier wave to transmit information to a receiving apparatus on the optical transmission path. The transmitting apparatus is disposed in each node and includes a determining unit that receives an input of information concerning unused sub-carriers of a transmission signal in the optical transmission path and determines transmission of the information to the receiving apparatus using an unused sub-carrier; an electrical frequency division multiplex transmission unit that using a frequency of the unused sub-carrier determined by the determining unit, modulates the input information to be transmitted to the receiving apparatus; and a coupling unit that adds to the transmission signal in the optical transmission path, a modulated modulation signal.

Abstract: A PON (Passive Optical Network) system, which modulates multiple subcarriers with data of multiple users to output an optical multiplexed signal from a station device, splits the optical multiplexed signal to transmit the split signals to multiple subscriber devices that are provided for each of the users, and demodulates the data of the users at the respective subscriber devices, includes: an obtaining section configured to obtain a transmission characteristic for each of the subcarriers at each of the subscriber devices, by receiving a test signal at the subscriber devices, which is transmitted from the station device; and an assigning section configured to assign one or more of the subcarriers for each of the subscriber devices suited to the transmission characteristics of the assigned subcarriers at each of the subscriber devices.

Abstract: An optical receiver includes an analog/digital converter, and a control circuit. The analog/digital converter has a dynamic range at a time of converting an analog electric signal generated based on an optical signal to a digital electric signal. The dynamic range is variable, and the control circuit varies the dynamic range of the analog/digital converter based on the chromatic dispersion of the optical signal.

Abstract: There is provided an optical network system in which optical signals modulated by each of at least two modulation methods are wavelength-division-multiplexed and transferred, including: an optical transmitter configured to transmit first optical signals modulated by each of at least two modulation methods; an add-drop multiplexer configured to drop second optical signals from wavelength-division-multiplexed optical signals transferred in the optical network system, and add the first optical signals to the wavelength-division-multiplexed optical signals; an optical receiver configured to demodulate the second optical signals corresponding to each of at least two modulation methods; and a controller configured to control wavelengths of the first optical signals, the second optical signals and the wavelength-division-multiplexed optical signals so as to rearrange wavelengths of the first optical signals, the second optical signals and the wavelength-division-multiplexed optical signals so that optical signals mo

Abstract: Laminated ceramic capacitors include ceramic layers and inner electrodes that are alternately laminated. The inner electrodes are laminated in the same lamination direction, and a first outer electrode and a second outer electrode are electrically connected to the inner electrodes. In a mounting process, the laminated ceramic capacitors are mounted on a mounting surface such that the inner electrodes are perpendicular or substantially perpendicular to the mounting surface.

Abstract: An optical transmitter is provided for transmitting a wavelength multiplexed signal comprising an intensity modulation optical signal and a phase modulation optical signal through a transmission line. The optical transmitter includes a bit time difference given signal generator for generating at least two optical signals having a bit time difference therebetween, from the wavelength multiplexed signal. The optical transmitter further includes a wavelength multiplexed signal output unit to which at least two optical signals are input from the bit time difference given signal generator, and which generates and outputs a wavelength multiplexed signal in which the bit time difference was given between the phase modulation optical signal and the phase modulation optical signal.

Abstract: The disclosed optical transmitter and control method include performing phase modulation of a light propagating through a corresponding optical path in accordance with a data signal, supplying bias voltages for regulating an operating point of each of phase modulation performed, imparting a predetermined phase difference, supplying bias voltages for phase difference regulation and coupling lights output from the corresponding optical paths. The optical transmitter includes superimposing a pilot signal on either one of bias voltages where the pilot signal has a frequency lower than a frequency of a bit rate of the data signal, and performing a feedback control in accordance with a result of monitoring.

Abstract: An optical modulation device including waveform shapers that waveform-shape input data signals in synchronism with a rising or falling timing based on comparison with a reference level of an input clock signal, a multi-level phase modulator that generates a multi-level-phase-modulated optical signal based on the data signals waveform-shaped by the plurality of waveform shapers, and outputs the generated optical signal, and a level ratio controller that varies a relative level ratio of the reference level to an amplitude level of the clock signal input to the waveform shapers, based on the optical signal output from the multi-level phase modulator.

Abstract: A polarized-wave-multiplexing optical transmitter including: an optical combiner generating a polarized-wave-multiplexed optical signal by polarized-wave-multiplexing a first optical modulation signal and a second optical modulation signal; an optical power fluctuation portion fluctuating optical power of the first optical modulation signal and the second optical modulation signal periodically; a total-optical-power detection portion detecting fluctuation amount of total optical power of the polarized-wave-multiplexed optical signal; and an optical power controller reducing an optical power difference between the first optical modulation signal and the second optical modulation signal based on detection result of the total-optical-power detection portion.

Abstract: The embodiments of the present invention provide a method and an apparatus for compensating nonlinear distortions in an intensity modulation-direct detection (IM-DD) system; wherein the method comprises: calculating, according to nonlinear coefficients and differences between values of an input signal at different time, nonlinear distortions of the input signal, so as to eliminate the nonlinearity distortions. By applying the method and the apparatus provided by the embodiments of the present invention, nonlinear cost of the IM-DD system can be effectively reduced, thereby improving the system capacity.

Abstract: An optical power monitor that detects optical power of respective wavelengths of a signal light in a wavelength multiplexing system, includes: a light emitter configured to superimpose a frequency modulation component on a signal light; a wavelength tunable filter configured to sweep a pass band of the signal light across a wavelength band for a signal light; and a detector configured to detect intensity changes in optical power passing through the wavelength tunable filter with a frequency modulation of the optical power, and to detect an optical power measurement value at a middle point of two points of the intensity changes of the optical power as the optical power of a wavelength to be measured.

Abstract: An optical transmission system for communicating between transmission devices includes a first pump light source that supplies a first pump light, a second pump light source that supplies a second pump light, an optical transmission line that propagates an optical signal between the transmission devices, and a plurality of couplers that form a plurality of zones in the transmission line, the first pump light source and the second pump light source being optically connected to different couplers of the plurality of couplers, the second pump light Raman-amplifying the first pump light in a zone in which the second pump light is input in the transmission line.

Abstract: A heat sink including a base section, connection fins, and parallel fins. The base section includes: a first base plate configured to be mounted with a heat generating component on its outer surface; a second base plate disposed to face the first base plate in a parallel manner, configured to be mounted with a heat generating component on its outer surface; and a third base plate disposed perpendicular to the first base plate and the second base plate, which secures the first base plate and the second base plate along a junction line. The base section includes first and second regions arranged in the direction of the junction line. The connection fins are disposed on the first region to connect inner surfaces of the first and second base plates and to be parallel to the third base plate, and the parallel fins are disposed on the second region from an inner surface of the third base plate to be parallel to the first base plate.

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.