| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical transmission device, etc. having high transmission quality and resistance to environmental changes and capable of transmitting a large volume of data.SOLUTION: A delay control circuit 30 outputs two reference signal clocks having had their phase delay adjusted against a standard reference clock. In modulation signal generation circuits 20-1 and 20-2, a CMU generates multiplied clocks by multiplying the reference signal clocks synchronously with the reference signal clocks and divided clocks by diving the multiplied clocks. An FIFO writes data into memory with main signal clocks keeping pace with externally input parallel main signals and reads out the data written into memory with the reference signal clocks. A mapper processing unit, an MUX and a DA converter generate, from the parallel main signals input from the FIFO, a modulation signal to be input to an Ich modulation unit and to a Qch modulation unit of an optical modulator 10. A delay control circuit 30 compares the phases of the divided clocks generated by the CMU to adjust a delay. |
