| 摘要 |
An optical, transmitter with a stabilized operating point for an optical transmitter, especially for that including a Mach-Zehnder optical modulator, is disclosed. An optical modulator is provided which modulates a light beam from a light source according to a driving voltage from a drive circuit. An operating point stabilizing circuit is provided which detects a drift in the characteristic curve from the optical modulator and controls the optical modulator to bring the operating point to a specified position. Deterioration in the waveform of the output optical signal due to the operating point drift is thereby prevented without depending on the input signal. Further, by performing an operating point shift under specific conditions, deterioration in the waveform due to wavelength dispersion can be effectively prevented, whether the sign of the wavelength dispersion is positive or negative. |
