A laser driving apparatus for a light source of an optical head apparatus
includes a laser, a laser driving circuit, and a radio frequency current
generation circuit for generating a radio frequency current to be
superimposed on the drive current. The laser driving apparatus further
includes a current monitor circuit, an optical detector for detecting an
optical output of the laser; a selection circuit for selecting either of
non-superimposing or superimposing the radio frequency current on the
drive current, an APC circuit for controlling the optical output of the
laser at a constant level, and a control circuit. The control circuit
controls the amplitude of the radio frequency current on the basis of
current values of the drive current on non-superimposing and
superimposing or detection values of the optical output of the laser on
non-superimposing and superimposing.