| 摘要 |
PURPOSE:To control an identification signal fed to a filter incident optical signal independently of its phase state by reducing number of identification signals to be fed to a light source into one signal for each light source so as to attain the automatic rising of the control system. CONSTITUTION:In order to implement tracing control of a transmission center wavelength of a wavelength filter 120 being the controlled system to a wavelength filter input optical wavelength, the transmission center wavelength of the wavelength filter is modulated minutely by an oscillator 161 to discriminate a phase change in a modulation component of a wavelength filter output light in this case. Moreover, the transmission center wavelength of the wavelength filter 120 being the controlled system is swept at the rising of the controller and the sweeping is stopped when one wave of the wavelength multiplex light being the input light to the wavelength filter (not necessary to be coincident with the transmission center wavelength set at the rising) is transmitted through the wavelength filter and the usual automatic tuning control tracing control is transited. Furthermore, the phase of an output pulse of a frequency synthesizer 180 is minutely modulated. |
