Patent ID: 6922418

Claim:
A wavelength-variable light source apparatus comprising: a semiconductor laser light source section; an external resonance section for externally resonating emitted light from said semiconductor laser light source section at a predetermined wavelength; a drive section for varying an external resonance condition in said external resonance section; a control section for controlling the external resonance condition in said drive section, said control section outputting a control signal for controlling the external resonance condition; a light detection section for detecting a light output level of the emitted light from said semiconductor laser light source section; a light source drive control section for correcting a drive signal supplied to said semiconductor laser light source section based on the light output level detected by said light detection section or controlling the light output level to a constant level; a storage section for storing a wavelength correction value corresponding to the wavelength of the emitted light from said semiconductor laser light source section; and a count section, not controlled by a CPU, for counting an address for reading the wavelength correction value stored in said storage section based on the control signal output from said control section, wherein said light source drive control section corrects the drive signal supplied to said semiconductor laser light source section based on the wavelength correction value read from said storage section according to the address counted by said count section for controlling the light output level to a constant level.