Abstract: An optical transmitter includes a dummy optical source, a polarized wave beam coupler, and an auto gain control (AGC)-system amplifier. The dummy optical source outputs, out of an optical signal in which an optical path signal and an optical packet signal are mixed, a dummy signal having a wavelength identical to that of the optical packet signal. The polarized wave beam coupler multiplexes the dummy signal with the optical signal so that the dummy signal is orthogonal to the optical signal so as to output an output signal. The AGC-system amplifier inputs the output signal, and amplifies the output signal with a predetermined amplification factor corresponding to a power difference between input power and output power of an optical amplifier.

Abstract: A transmission device includes a first optical modulator configured to modulate, based on a packet signal for each of packets, input light into an optical packet signal and to output an optical packet signal for each of the packets; a generation circuit configured to generate an adjustment signal that adjusts slopes of a rise and a fall of a waveform of the optical packet signal; and a second optical modulator configured to modulate the optical packet signal from the first optical modulator and adjust, based on the adjustment signal, the slopes of the rise and the fall of the waveform of the optical packet signal.

Abstract: An optical transmitter includes an amplifying unit, a monitor, an identifying unit, and a controlling unit. The amplifying unit amplifies an optical signal in which an optical packet signal is mixed in optical path signals. The monitor monitors power of the optical signal on an input stage and an output stage of the optical amplifying unit, respectively. The identifying unit identifies an optical packet signal section on the input stage side based on the monitoring result on the input stage side, and identifies an optical packet signal section on the output stage side based on the monitoring result on the output stage side. The controlling unit compares the power of the identified section on the input stage side with the power of the identified section on the output stage side, and controls an amplification factor of the amplifying unit based on a power difference resulting from the comparison.

Abstract: The optical transmission device includes an N×N optical switch, an optical packet receiver and an optical packet generation unit. The N×N optical switch transmits data in which a plurality of optical signals each having a different wavelength is multiplexed. The optical packet receiver detects change in the number of wavelengths of optical signals constituting the data. The optical packet generation unit generates, when the change is detected by the optical packet receiver, data to be transmitted by the N×N optical switch, using optical signals for the number of wavelengths after the change.

Abstract: An optical communication apparatus includes a variable resistor unit, a measurement unit, and a control unit. The variable resistor unit is arranged at a pre-stage of an electrical/optical conversion unit, which converts an electrical signal obtained by converting an input packet to an optical signal having a waveform corresponding to a potential difference between a positive phase component and a negative phase component of the electrical signal by using the potential difference. The variable resistor unit provides a resistor that varies a midpoint of potential of the positive phase component or the negative phase component. The measurement unit measures a ratio of a presence period, which is a period where the input packet is present, to a sum of the presence period and a non-presence period. The control unit controls a value of the resistor provided to the positive phase component or the negative phase component based on the ratio.

Abstract: An optical transmitter includes an amplifying unit, a monitor, an identifying unit, and a controlling unit. The amplifying unit amplifies an optical signal in which an optical packet signal is mixed in optical path signals. The monitor monitors power of the optical signal on an input stage and an output stage of the optical amplifying unit, respectively. The identifying unit identifies an optical packet signal section on the input stage side based on the monitoring result on the input stage side, and identifies an optical packet signal section on the output stage side based on the monitoring result on the output stage side. The controlling unit compares the power of the identified section on the input stage side with the power of the identified section on the output stage side, and controls an amplification factor of the amplifying unit based on a power difference resulting from the comparison.

Abstract: An optical transmitter includes a dummy optical source, a polarized wave beam coupler, and an auto gain control (AGC)-system amplifier. The dummy optical source outputs, out of an optical signal in which an optical path signal and an optical packet signal are mixed, a dummy signal having a wavelength identical to that of the optical packet signal. The polarized wave beam coupler multiplexes the dummy signal with the optical signal so that the dummy signal is orthogonal to the optical signal so as to output an output signal. The AGC-system amplifier inputs the output signal, and amplifies the output signal with a predetermined amplification factor corresponding to a power difference between input power and output power of an optical amplifier.

Abstract: An optical transmission device that receives a wavelength division multiplexed optical signal obtained by dividing an optical packet signal and performing wavelength multiplexing and that transmits via an optical switch the received wavelength division multiplexed optical signal includes an optical power level measurement unit configured to measure respective optical power levels of respective optical signals of wavelengths included in the wavelength division multiplexed optical signal, and a routing information determinator configured to determine routing information of the wavelength division multiplexed optical signal on the basis of the measured optical power levels.

Abstract: An optical packet switching system includes an optical packet transmitter, an optical packet switching apparatus, an optical amplifier, an optical packet receiver, an information gathering unit, and a peak power calculation unit. The information gathering unit collects the packet density, time-averaged power and extinction ratio from the optical packet transmitter, collects the packet density, time-averaged power and noise figure from the optical amplifier, collects the packet density, time-averaged power, switch on/off time ratio and extinction ratio from the optical packet switching apparatus, and collects the packet density and time-averaged power from the optical packet receiver. The peak power calculation unit calculates the peak power of an optical packet signal outputted from each apparatus/device based on the collected information.

Abstract: An optical transmission system includes a transmission side optical transmission apparatus having a transmitting unit configured to transmit optical signals of a predetermined number of differing wavelengths, and a processor configured to apply to the optical signals transmitted from the transmitting unit, a predetermined offset related to a tilt; and a reception side optical transmission apparatus having a receiving unit configured to receive the optical signals transmitted from the transmitting unit, a measuring unit configured to measure an optical signal count of the optical signals receivable by the receiving unit, and a notifying unit configured to give notification of the optical signal count measured by the measuring unit. The processor adjusts the offset in an increasing direction when the optical signal count notified by the notifying unit increases, and adjusts the offset in a decreasing direction when the optical signal count notified by the notifying unit decreases.

Abstract: The optical transmission device includes an N×N optical switch, an optical packet receiver and an optical packet generation unit. The N×N optical switch transmits data in which a plurality of optical signals each having a different wavelength is multiplexed. The optical packet receiver detects change in the number of wavelengths of optical signals constituting the data. The optical packet generation unit generates, when the change is detected by the optical packet receiver, data to be transmitted by the N×N optical switch, using optical signals for the number of wavelengths after the change.

Abstract: An optical communication apparatus includes a variable resistor unit, a measurement unit, and a control unit. The variable resistor unit is arranged at a pre-stage of an electrical/optical conversion unit, which converts an electrical signal obtained by converting an input packet to an optical signal having a waveform corresponding to a potential difference between a positive phase component and a negative phase component of the electrical signal by using the potential difference. The variable resistor unit provides a resistor that varies a midpoint of potential of the positive phase component or the negative phase component. The measurement unit measures a ratio of a presence period, which is a period where the input packet is present, to a sum of the presence period and a non-presence period. The control unit controls a value of the resistor provided to the positive phase component or the negative phase component based on the ratio.

Abstract: An optical transmission device that receives a wavelength division multiplexed optical signal obtained by dividing an optical packet signal and performing wavelength multiplexing and that transmits via an optical switch the received wavelength division multiplexed optical signal includes an optical power level measurement unit configured to measure respective optical power levels of respective optical signals of wavelengths included in the wavelength division multiplexed optical signal, and a routing information determinator configured to determine routing information of the wavelength division multiplexed optical signal on the basis of the measured optical power levels.

Abstract: An optical transmission device that is installed at a node of a network and that performs transmission of an optical signal transmits the optical signal to an optical transmission device at the next node without amplifying the optical signal. The optical transmission device generates an adjustment optical signal used by a reception-side optical amplifier in the optical transmission device at the next node to adjust gain for a transmission loss of the optical signal. At the time of booting of the optical transmission device, the optical transmission device transmits the generated adjustment optical signal to the reception-side optical amplifier in the optical transmission device at the next node. Upon receiving a gain-adjustment-completion signal for notifying completion of gain adjustment using the adjustment optical signal from the reception-side optical amplifier, the optical transmission device controls the transmission of the adjustment optical signal to be stopped.

Abstract: An optical transmission apparatus includes a splitter configured to split an input optical signal into a first optical signal and a second optical signal, a signal length determiner configured to determine a signal length of the first optical signal per unit time, an optical power detector configured to detect an optical power of the first optical signal per unit time, a delay unit configured to delay the second optical signal, an optical amplifier configured to amplify the second optical signal delayed by the delay unit, a first excitation light source configured to generate an excitation light to be supplied to the optical amplifier, and a first excitation light power adjustor configured to adjust an optical power of the excitation light to be supplied to the optical amplifier in accordance with the signal length of the first optical signal and the optical power of the first optical signal.

Abstract: An optical packet switching system includes an optical packet transmitter, an optical packet switching apparatus, an optical amplifier, an optical packet receiver, an information gathering unit, and a peak power calculation unit. The information gathering unit collects the packet density, time-averaged power and extinction ratio from the optical packet transmitter, collects the packet density, time-averaged power and noise figure from the optical amplifier, collects the packet density, time-averaged power, switch on/off time ratio and extinction ratio from the optical packet switching apparatus, and collects the packet density and time-averaged power from the optical packet receiver. The peak power calculation unit calculates the peak power of an optical packet signal outputted from each apparatus/device based on the collected information.

Abstract: A measurement apparatus for measuring an optical fiber transmission line used to connect to an opposite apparatus, the measurement apparatus includes a transmission part for generating a measurement packet used for measuring a length of a first and second optical fiber transmission line, and transmitting the measurement packet to the opposite apparatus through the first optical fiber transmission line, a reception part for detecting the measurement packet returned from the opposite apparatus that perform a loopback processing of the measurement packet through the second optical fiber transmission line, a calculation part for calculating a packet transmission time which is a processing time required from the generation of the measurement packet to the detection of the measurement packet, and a measurement part for performing a measurement control of the length of the first and second optical fiber transmission line based on the packet transmission time calculated by the calculation part.

Abstract: A wavelength-multiplexing optical transmission apparatus includes an optical-wavelength-information storing unit that stores optical wavelength information on an optical wavelength of an optical signal to be output from a transponder, and an optical-wavelength-information transmitting unit that transmits the stored optical wavelength information to the transponder via a connection cable. The transponder includes an optical-wavelength control unit that controls an optical wavelength of an optical signal to be input to a wavelength multiplexing unit based on the optical wavelength information received from the optical-wavelength-information transmitting unit.

Abstract: An optical WDM transmission apparatus includes plural optical attenuators that respectively attenuate the power of optical signals separated according to wavelength; plural first optical receivers that respectively detect the power of the attenuated optical signals; a multiplexer that multiplexes the optical signals; a second optical receiver that detects the power of the multiplexed optical signal; and a monitoring control unit that includes a first control system that controls the optical attenuators so that the powers detected at the first optical receivers respectively become target values, and a second control system that, based on the power detected by the second optical receiver and information concerning the number of wavelengths corresponding to the optical signals input, controls the optical attenuators so that the powers of the optical signals respectively become the target values.

Abstract: A measurement apparatus for measuring an optical fiber transmission line used to connect to an opposite apparatus, the measurement apparatus includes a transmission part for generating a measurement packet used for measuring a length of a first and second optical fiber transmission line, and transmitting the measurement packet to the opposite apparatus through the first optical fiber transmission line, a reception part for detecting the measurement packet returned from the opposite apparatus that perform a loopback processing of the measurement packet through the second optical fiber transmission line, a calculation part for calculating a packet transmission time which is a processing time required from the generation of the measurement packet to the detection of the measurement packet, and a measurement part for performing a measurement control of the length of the first and second optical fiber transmission line based on the packet transmission time calculated by the calculation part.