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.