Patent ID: 6888861

Claim:
A semiconductor laser apparatus comprising: a semiconductor laser; a light intensity detector configured to detect intensity of a laser beam output from the semiconductor laser; an amplifying circuit including a non-reversal input terminal and a reversal input terminal that are each configured to receive predetermined input signals the reversal input terminal being further configured to receive an output signal from the light intensity detector as a negative feedback signal; a high-frequency signal generating circuit configured to generate a high-frequency signal having a predetermined frequency; a high-frequency signal superimposing circuit configured to superimpose the high-frequency signal onto an output signal of the amplifying circuit; a laser drive circuit configured to supply a drive current to the semiconductor laser on the basis of an output signal from the amplifying circuit having the superimposed high frequency signal thereon; and a modulation signal current generating section configured to apply a modulation signal current to the reversal input terminal of the amplifying circuit so as to adjust an amount of laser beam light from the semiconductor laser.