| 摘要 |
PURPOSE:To control the wavelength of a semiconductor laser in a manner easy to be most stabilized at all times by making sure the value of a wavelength-detecting signal at a point of time when a delimiting signal is inputted in a high-frequency pulse overlapping section and determining a wavelength oscillating most stably. CONSTITUTION:When a delimiting signal PS is inputted to a high-frequency pulse overlapping section 9, the overlapping of high-frequency pulses is suspended, a wavelength oscillating under the state in which high-frequency pulses are not overlapped is detected by a wavelength detecting section 11, and the value of the wavelength is inputted to the high-frequency pulse overlapping section 9. Consequently, a stable wavelength under conditions in which high-frequency pulses for stabilizing the wavelength are not applied is detected, and the parameter of high-frequency pulses is adjusted so that the oscillating wavelength of a semiconductor laser LD is held at the previously detected stable wavelength when a modulation signal MS is inputted. Accordingly, the value of the stable wavelength under normal conditions in which high-frequency pulses are not overlapped is detected every time the delimiting signal PS is inputted, and the parameter of high-frequency pulses is adjusted so that said wavelength is maintained. |
