Abstract: A printer having holographic scanning disc for scanning the imaging beam from a laser diode across a recording member, the diode having diode biasing and modulating current inputs for modulating the diode and thereby exposing and creating images on the recording member, a heating-cooling device in heat exchange relation with the diode for controlling diode temperatures, and a current sensor for monitoring the diode biasing and modulating currents and operating the heating-cooling device to adjust diode temperatures to maintain diode temperatures within a non-mode hopping temperature range.

Abstract: A dynamic power control for an external cavity stabilized laser diode adapted for use with a Raster Output Scanner employing a photodiode to convert light emitted from the rear facet of the diode internal cavity to an electrical signal, and a comparator for comparing the light intensity signal with a reference signal and adjusting the drive current input to the diode to maintain diode output pwer constant. In a second embodiment, diode power is taken from the zero order beam at the external cavity transmissive wavelength selecting grating, in a third embodiment from the external cavity output beam, and in a fourth embodiment, from the zero order beam that passes through the holographic disc facets.