| 摘要 |
An optical modulator performing chromatic compensation and optical time division multiplexing (OTDM). The optical modulating device comprises, for example, an optical switch 6 for generating first and second optical clock signals 8 from a carrier beam 4 output by a light source 2, and optical modulators 10 for respectively switching on/off the optical clock signals 8 by data signals 12 to generate first and second signal beams 14. An optical multiplexer 16 then combines the signal beams 14 to generate an OTDM signal 20, which is sent down an optical fibre 18. A prechirp circuit 22 controls one or more of the aforementioned components in order that the OTDM signal 20 has a chirp parameter adapted for the optical transmission line 18 in order to precompensate the signal for chromatic dispersion. The invention therefore allows high-speed transmission of chromatically compensated signals. The optical modulators 10 may be of the Mach-Zehnder type. Other arrangements of components are also disclosed as are embodiments with more than two clock generators and data modulators and an embodiment which uses a pulsed light source and has no clock generators. |
