| 摘要 |
PROBLEM TO BE SOLVED: To provide a device and a method for converting a nonreturn-to- zero(NRZ) voltage data stream into an optical data stream of a return-to-zero(RZ) format. SOLUTION: A continuous optical signal is fed to a modulator 16, and the modulator 16 is provided with a minimum optical output in the first voltage driving level, a minimum optical output in the second voltage level, and a maximum optical output in the voltage level between the first voltage level and the second voltage level. After a NRZ voltage data stream is coded, the modulator 16 is driven by means of the coded NRZ voltage data stream so as to generate a RZ optical data stream so that the maximum optical output is provided when the coded NRZ voltage data stream is transferred from the first voltage level to the second voltage level, or from the second voltage level to the first voltage level. For the modulator 16, an interferometer such as a Mach-Zehnder interferometer, or a directional coupler can be used, for example. |
