摘要 |
The device comprises two modulators imposing power and phase modulation on optical signal. The transmission device comprises a first electro-optic modulator (1,2) which responds to an electrical input signal (E), producing a phase controlled optical signal (S) with an optical power modulated between low and high levels. The signal has a phase shift within each time cell which contains a low power level. In order to improve its flexibility of use, the device also comprises a second electro-optic modulator (3,4) controlled by the input signal (E), and optically coupled to the first modulator. This acts to apply to the phase controlled optical signal a complementary power and/or phase, in order to modify the its extinction rate and/or give to the signal a transitory 'chirp'. |