A tunable laser is disclosed including a gain section for creating a light beam
over a bandwidth, a phase section for controlling the light beam around a center
frequency of the bandwidth, a waveguide for guiding and reflecting the light beam
in a cavity including a relatively low energy bandgap separate-confinement-heterostructure
(SCH), a front mirror bounding an end of the cavity and a back mirror bounding
an opposite end of the cavity wherein gain is provided by at least one of the group
comprising the phase section, the front mirror and the back mirror.
