| 摘要 |
PROBLEM TO BE SOLVED: To improve transmission characteristics by generating an RZ optical pulse corresponding to a data signal to be transmitted by an RZ optical pulse generation means and suppressing, i.e., flatening or recessing, the peak part of an optical pulse outputted from the RZ optical pulse generation means by a peak suppression means. SOLUTION: A laser light source 10 generates CW laser light of prescribed wavelength and an optical intensity modulator 14 modulates the optical intensity of output light from the laser light souruce 10 in accordance with a digital data signal inputted from a data input terminal 12 to generate an RZ optical pulse. A sine wave generation circuit 16 extracts a clock component from the digital data signal inputted from the terminal 12, generates a sine wave signal having the frequency of the extracted clock component and impresses the sine wave signal to an optical intensity modulator 18, a phase modulator 20 and a polarization modulator 22. The modulator 18 modulates the optical intensity of the RZ pulse signal outputted from the modulator 14 so that the pulse peak part of the RZ pulse signal is recessed like an M shape in accordance with the output from the circuit 16. The modulator 20 modulates the phase of output light from the modulator 18 in accordance with the output of the circuit 16 and the modulator 22 modulates the polarization of the output light front the modulator 18 in accordance with the output of the circuit 16. |
