The present invention is directed to a method and system for providing a
three-level current scheme to a semiconductor laser to control beam
wavelength and laser temperature. A first current is received into a gain
section of the semiconductor laser and at least one other current is
received into a DBR and/or phase section of the semiconductor laser. This
other current(s) is pulse-width modulated based upon a required
temperature value. An output beam is generated by the semiconductor laser
based upon the received first current and the received pulse-width
modulated current(s).