摘要 |
In an optical communication system, there are provided an optical transmission path, a terminal, and a transmitter. The transmitter includes at least one light source, a plurality of external light modulators for modulating respective lights from the at least one light source according to a signal from the terminal, and a coupler means for combining modulated lights from the external light modulators into a single light to transmit this single light to the optical transmission path. As a result, the present invention can preferably be applied to a multi-value digital optical communication system, and therein a complicated modulation control device is unnecessary for obtaining a signal light intensity accurately modulated in a multi-valued form. <IMAGE> |