| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a multi-value optical transmitter which can stabilize optical transmission signal quality by performing stabilizing control on a DC bias when multi-value modulation is executed using a dual-electrode MZ modulator. <P>SOLUTION: The multi-value optical transmitter includes: D/A converters 11a and 11b that perform D/A conversion on first modulation data and second modulation data according to input data series to generate a first multi-value signal and a second multi-value signal, respectively; the dual-electrode MZ modulator 14 which includes phase modulators 14a and 14b that respectively modulate light beams from a light source 13 according to the first multi-value signal and the second multi-value signal, and combines an optical signal from the phase modulator 14a and an optical signal from the phase modulator 14b to output an optical multi-value signal; an optical output power monitor 16 that detects an average power of the optical multi-value signal; and a DC bias controlling section that controls the DC bias for the dual-electrode MZ modulator 14 so that the average power becomes a maximum. <P>COPYRIGHT: (C)2011,JPO&INPIT |
