Distributed-feedback semiconductor laser with quantum well structured optical modulator and manufacture thereof

PURPOSE: To provide an integrated light source capable of smoothly connecting the refractive indices of MQW structures in different effective forbidden band width energies by providing a separating part in the third clad layer. CONSTITUTION: The title distribution feedback type semiconductor laser is provided with an active layer 26 arranged on a substrate 20, a distributed-fedback laser part 12 having the first upper and lower clad layers 30, 24 and an optical modulator 13 having the second clad layers 36, 32 holding the second waveguid layer 34 coupled with the semiconductor laser part 12. The semiconductor laser part 12 and the optical modulator 13 have the third clad layer 38 while the multiquantum well structures 26, 34 are isolated from each other on a surface perpendicular to the waveguide direction as well as optically connected in a photocoupling region 16 through the intermediary of the first and second lower clad layer 24, 32. Furthermore, this semiconductor laser commonly holds the ends only opposite to the interface 17 of the first and second semiconductor parts 14, 15 of the multiquantum well structures 26, 34 while the third clad layer 38 is provided with an isolation part 40 arranged along the region including the opposite ends 14A holding the interface 17. COPYRIGHT: (C)1993,JPO&Japio