A control circuit for a laser diode includes a power controller and a wavelength
controller. The power controller adjusts a bias current to the laser diode to change
the power output of the laser diode. The power change can have a corresponding
wavelength shift effect on the nominal operating wavelength of the laser diode.
The wavelength controller compensates for the wavelength shift such that the laser
diode maintains operation at the nominal wavelength. The circuit provides for electrical
control of the laser output power without the need for a costly and bulky optical
attenuator. The circuit also provides wavelength control to compensate for the
relationship between laser diode operating temperature and wavelength.