Laser diode driver system

Abstract

A laser diode driver solves problems of APC (Auto Power Control) group, a LD monitor group, and an optical output waveform, which occur when reducing adjusting resistors constituted in a conventional laser diode drive. The laser diode driver includes a laser diode for emitting a light output corresponding to an input signal, a light-receipt element for receiving a part of the light output emitted from the laser diode and outputting a light-receipt signal current corresponding to the received part of the light output, a driver circuit operatively coupled to the laser diode for supplying a driving current, which drives the laser diode to emit the light output, a duty variable controller for varying duty of a waveform of the driving current, an optical output stabilization loop for detecting a peak value corresponding to the light-receipt current outputted from the light-receipt element, comparing the detected peak value with a first reference value, and controlling the driver circuit to output a size of the driving current according to the difference between the detected peak value and the first reference value, and a duty stabilization loop for detecting an average value corresponding to the light-receipt signal current outputted from the light-receipt element, comparing the detected average with a second reference value, and controlling the duty variable controller to output the duty of the waveform of the driving current according to the difference between the detected average value and the second reference value.