Abstract: Provided is an optical communication cross-connection device for exchanging an OTN signal through optical communications, including: a plurality of OTN signal processing units (OTNsp units) for asynchronously conducting OTN signal processing; and a space switch connected between the plurality of OTNsp units, for conducting bidirectional signal exchange for the OTN signal, in which a first and a second OTNsp units that conduct signal transmission among the plurality of OTNsp units subject the OTN signal to skew processing on one side and deskew processing corresponding to the skew processing on another side between the first and second OTNsp units or between a communicating end-side one of the first and second OTNsp units and a communicating end-side OTNsp unit of an optical communication cross-connection device of a communication counterpart destination for the optical communication cross-connection device, and share a clock for the signal transmission therebetween.

Abstract: Provided is an optical communication cross-connection device for exchanging an OTN signal through optical communications, including: a plurality of OTN signal processing units (OTNsp units) for asynchronously conducting OTN signal processing; and a space switch connected between the plurality of OTNsp units, for conducting bidirectional signal exchange for the OTN signal, in which a first and a second OTNsp units that conduct signal transmission among the plurality of OTNsp units subject the OTN signal to skew processing on one side and deskew processing corresponding to the skew processing on another side between the first and second OTNsp units or between a communicating end-side one of the first and second OTNsp units and a communicating end-side OTNsp unit of an optical communication cross-connection device of a communication counterpart destination for the optical communication cross-connection device, and share a clock for the signal transmission therebetween.

Abstract: An optical channel data unit (ODU) switch includes a set of two or more client cards, a set of two or more line cards, and a set of two or more switch cards. Each switch card is connected to all client cards, all line cards, and all other switch cards, and each client card, line card and switch card includes control logic for managing an operation of the ODU switch in a distributed manner.

Abstract: An optical channel data unit (ODU) switch includes a set of two or more client cards, a set of two or more line cards, and a set of two or more switch cards. Each switch card is connected to all client cards, all line cards, and all other switch cards, and each client card, line card and switch card includes control logic for managing an operation of the ODU switch in a distributed manner.

Abstract: An optical transmitter for converting an input data series into an optical multi-level signal and for outputting the same, includes an LUT in which data for executing optical multi-level modulation is stored and from which first modulation data and second modulation data are output based on the input data series. A DAC converts the first modulation data by D/A conversion to generate a first multi-level signal. A DAC converts the second modulation data by D/A conversion to generate a second multi-level signal. A dual-electrode MZ modulator includes a first phase modulator for modulating light from a light source in accordance with the first multi-level signal and a second phase modulator for modulating light from the light source in accordance with the second multi-level signal, and combines an optical signal from the first phase modulator and an optical signal from the second phase modulator to output the optical multi-level signal.

Abstract: Provided is a multi-value optical transmitter in which a DC bias may be controlled to be stabilized so as to obtain stable optical transmission signal quality in multi-value modulation using a dual-electrode MZ modulator. The multi-value optical transmitter includes: D/A converters for performing D/A conversion on first and second modulation data which are set based on an input data series, so as to generate a first and a second multi-value signal, respectively; a dual-electrode MZ modulator including phase modulators for modulating light from a light source based on the first multi-value signal and the second multi-value signal, so as to combine optical signals from the phase modulators to output the optical multi-value signal; an optical output power monitor for detecting average power of the optical multi-value signal; and a DC bias control unit for controlling a DC bias for the dual-electrode MZ modulator, so as to maximize the average power.

Abstract: An optical transmitter for converting an input data series into an optical multi-level signal and for outputting the same, includes an LUT in which data for executing optical multi-level modulation is stored and from which first modulation data and second modulation data are output based on the input data series. A DAC converts the first modulation data by D/A conversion to generate a first multi-level signal. A DAC converts the second modulation data by D/A conversion to generate a second multi-level signal. A dual-electrode MZ modulator includes a first phase modulator for modulating light from a light source in accordance with the first multi-level signal and a second phase modulator for modulating light from the light source in accordance with the second multi-level signal, and combines an optical signal from the first phase modulator and an optical signal from the second phase modulator to output the optical multi-level signal.

Abstract: Provided is a multi-value optical transmitter in which a DC bias may be controlled to be stabilized so as to obtain stable optical transmission signal quality in multi-value modulation using a dual-electrode MZ modulator. The multi-value optical transmitter includes: D/A converters for performing D/A conversion on first and second modulation data which are set based on an input data series, so as to generate a first and a second multi-value signal, respectively; a dual-electrode MZ modulator including phase modulators for modulating light from a light source based on the first multi-value signal and the second multi-value signal, so as to combine optical signals from the phase modulators to output the optical multi-value signal; an optical output power monitor for detecting average power of the optical multi-value signal; and a DC bias control unit for controlling a DC bias for the dual-electrode MZ modulator, so as to maximize the average power.