Dispersion compensating apparatus, dispersion compensating method, optical receiving apparatus, and optical receiving method

A dispersion compensating apparatus comprising:

• 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 measurement device that measures power of a specific frequency component obtained after photoelectric conversion of the optical signal that has been dispersion-compensated by the tunable dispersion compensator;
• and
• a shifter that shifts a central frequency of the effective band of the tunable dispersion compensator in a shift direction that corresponds to the power measured by the measurement device.

An optical receiving apparatus comprising:

• 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 receiver device that receives the optical signal that has been dispersion-compensated by the tunable dispersion compensator;
• a measurement device that measures quality of the optical signal that is received by the receiver device;
• and
• a shifter that shifts a central frequency of the effective band of the tunable dispersion compensator in a shift direction for the quality measured by the measurement device to be improved.

An optical receiving method that uses a tunable dispersion compensator that dispersion-compensates an optical signal using a group delay property that is asymmetrical in bands outside an effective band, the method comprising:

• receiving the optical signal that has been dispersion-compensated by the tunable dispersion compensator;
• measuring quality of the optical signal that is received at the receiving;
• and
• shifting a central frequency of the effective band of the tunable dispersion compensator in a shift direction for the quality measured at the measuring to be improved.

A dispersion compensating apparatus comprising:

• 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 tunable filter that attenuates the bands outside the effective band of the optical signal and has a filtering property that is variable and includes at least one among a central frequency of a transmission property and a bandwidth;
• a set device that sets a dispersion compensation amount in the tunable dispersion compensator;
• and
• a controller that controls the filtering property of the tunable filter, based on the dispersion compensation amount set by the set device.

An optical receiving apparatus comprising:

• 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 tunable filter that attenuates the bands outside the effective band of the optical signal and has a filtering property that is variable and includes at least one among a central frequency of a transmission property and a bandwidth;
• a receiver that receives the optical signal that has been dispersion-compensated by the tunable dispersion compensator;
• a measurement device that measures quality of the optical signal received by the receiver;
• and
• a controller that controls the filtering property of the tunable filter in a control direction for the quality measured by the measurement device to be improved.

An optical receiving method that uses a tunable dispersion compensator that dispersion-compensates an optical signal using a group delay property that is asymmetrical in bands outside an effective band and a tunable filter that attenuates the bands outside the effective band of the optical signal and has a filtering property that is variable and includes at least one among a central frequency of a transmission property and a bandwidth, the method comprising:

• receiving the optical signal that has been dispersion-compensated by the tunable dispersion compensator;
• measuring quality of the optical signal received at the receiving;
• and
• controlling the filtering property of the tunable filter in a control direction for the quality measured at the measuring to be improved.