Patent ID: 6842472

Claim:
A semiconductor laser element, comprising: a semiconductor laser region including a plurality of laser emission portions each having the same construction relative to one another and arranged side by side in a parallel array and having a common modulation electrode traversing and covering only the laser emission portions, each of said laser emission portions including an active layer for emitting light; a multimode interference region including a first wave-guiding layer; an input waveguide region located between the semiconductor laser region and the multimode interference region, said input waveguide region including a plurality of wave-guiding portions where all the wave-guiding portions are equal length in an optical direction; and an output waveguide region including a second wave-guiding layer, the second wave-guiding layer being optically coupled to an opposite end of the first wave-guiding layer of the interference region, wherein the material comprising the first wave-guiding layer is different from that of the active layers of the laser emission portions.