| 摘要 |
PROBLEM TO BE SOLVED: To surely execute a modulation processing by optimally and stably permitting the phase of an optical pulse signal to match that of a data signal for a long period even in the case when a super high speed optical pulse signal is modulated by means of the data signal. SOLUTION: The optical pulse signal inputted to an optical modulator 5 is converted into an electric signal by a photoelectric converter 8, a phase detector 9 detects phase difference between the electric signal and a data identifying clock signal, the input clock phase of an optical pulse generator 2 is controlled by a voltage control phase shifter 6 so as to eliminate the phase difference and, thus, the phase of the optical pulse signal inputted to an optical modulator 5 optimally and stably coincides with that of the data signal for the long period. |
