| 摘要 |
In order to shorten the convergence time in ABC control and minimize the reduction in reception sensitivity by a simple configuration while taking into consideration individual differences among modulators, this optical transmitter is provided with: an optical modulation unit to which are applied an optical carrier wave, a data signal for modulating the optical carrier wave, and a bias voltage onto which a pilot signal is superimposed, the bias voltage setting a carrier wave modulation point, and the optical modulation unit outputting a data signal-modulated carrier wave as output light, as well as outputting a monitor signal proportional to the amplitude of the output light; and a control unit for detecting from the monitor signal the amplitude of a first signal which is a signal of a frequency double that of the pilot signal, and performing feedback control of the bias voltage such that the amplitude of the first signal reaches maximum, as well as setting the amplitude of the pilot signal to a first amplitude when commencing feedback control, and when the amplitude of the first signal has increased, setting the amplitude of the pilot signal to a second amplitude lower than the first amplitude. |
