A semiconductor laser is provided comprising a semiconductor substrate, an
active region, a ridge waveguide, a driving electrode structure, and a
micro-heating element structure. The micro-heating element structure
comprises a pair of heating element strips extending along the
longitudinal dimension of the semiconductor laser. The heating element
strips are on opposite sides of the ridge waveguide such that one of the
heating element strips extends along one side of the ridge waveguide
while a remaining heating element strip extends along another side of the
ridge waveguide.