Patent ID: 6836489
Filing Date: 2004-12-28
Classification: H01S

Abstract:
A wavelength control apparatus that controls an oscillation wavelength of a wavelength variable semiconductor laser, the wavelength variable semiconductor laser having first and second light reflectors into which respective currents may be injected to control light reflection and an active layer area disposed between the first and second light reflectors, each of the first and second light reflectors having a plurality of reflection peaks at respective wavelengths, the wavelength control apparatus comprising:an oscillation state deciding section that decides an oscillation state of the wavelength variable semiconductor laser; and a drive controller that determines current conditions of an injection current injected into the first light reflector and an injection current injected into the second light reflector that produce single-mode oscillation at a target wavelength, by simultaneously sweeping the injection current injected into the first light reflector and the injection current injected into the second light reflector based on a decision made by the oscillation state deciding section, and controls driving of the wavelength variable semiconductor laser using the current conditions determined, wherein the drive controller searches for an oscillation-mode boundary of the wavelength variable semiconductor laser by simultaneously sweeping the injection current injected into the first light reflector and the injection current injected into the second light reflector based on the decision made by the oscillation state deciding section, and controls the sweeping of the injection current injected into the first light reflector and the injection current injected into the second light reflector for producing single-mode oscillation at the target wavelength based on the oscillation-mode boundary found by searching.