Patent ID: 7653093

Claim:
An integrated/semiconductor tunable optical laser comprising: an active waveguide structure for generating an emission; a passive tuning waveguide structure for guiding and tuning at least a portion of the emission generated by said active waveguide structure, wherein said active waveguide structure and said passive tuning waveguide structure are arranged to be perpendicular to a lasing direction of the laser, and wherein said passive tuning waveguide structure comprises at least two subsections each having a grating that are arranged along a single line that is parallel to the lasing direction of the laser; and at least two electrodes for applying a tuning current to each of said at least two subsections, wherein the passive tuning waveguide structure is located between said active waveguide structure and said at least two electrodes, and wherein the laser, in operation, is tuned using a respective single tuning current for each grating applied to said at least two electrodes, the respective tuning currents tuning the laser as a result of varying an effective refractive index of said passive tuning waveguide structure.