US Patent 7653093 Widely tunable twin guide laser structure

A widely tunable laser structure with at least two different sampled or superstructure gratings is provided. The widely tunable laser only requires as much tuning currents as gratings. In the case of two gratings, two tuning currents, instead of 3 tuning currents in a typical laser, are needed. Alternatively, the laser structure can be denoted a sampled or superstructure grating tunable laser with wide tunability characteristics, with a limited amount of needed tuning parameters, e.g., two currents.