| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital optical transmitter, an optical communication system, and a digital optical transmission method, capable of easily compensating an I-Q imbalance caused by changes in transmission conditions such as wavelength switching and temperature fluctuation.SOLUTION: A digital optical transmitter 10 comprises: an I-Q balance control unit 20 which generates a control signal corresponding to transmission conditions; a transmission data sequence arithmetic processing unit 30 which generates first data and second data on the basis of the control signal; an optical branching unit 40 which branches an optical signal into two optical signals; a first optical modulator 51 which optically modulates one of the branched optical signals on the basis of the first data and outputs the first optical signal; a second optical modulator 52 which optically modulates the other optical signal on the basis of the second data and outputs the second optical signal; and a coupling unit 60 which couples the first optical signal and the second optical signal at a prescribed phase difference &phgr;. The control signal cancels a deviation amount from the phase difference &phgr;. |
