| 摘要 |
PROBLEM TO BE SOLVED: To resolve difficulties in packaging technology of an optical phase modulator performing multi-value modulation, and to provide a compact optical phase modulator performing multi-value modulation having a simple structure.SOLUTION: An optical modulator 100 consists of m amplifiers 101-1 through 101-m, a combiner 102, a bias tee 103, and a semiconductor laser 104. The m amplifiers 101-1 through 101-m receive, respectively, one modulation signal and amplify the modulation signal thus received. The optical modulator 100 is set so that the amplification factor of the amplifier is V/2(here, Vis a voltage required for changing the phase by &pgr;), for m modulation signals. |
