Semiconductor laser, semiconductor optical amplifier, and production method thereof

摘要

The present innovation is as to provide a semiconductor laser capable of realizing a regular single mode output and achieving a high gain and high output as well as improving the COD level and the spatial hole burning and not causing a mode conversion loss in principle. The semiconductor laser comprises a single mode waveguide 1 and a multi-mode waveguide 2. The multi-mode waveguide 2 has a wider width than that of the single mode waveguide 1. The single mode waveguide 1 provides a single mode to an oscillated light oscillated from an active light waveguide. While the multi-mode waveguide 2 provides modes including a multi-mode to the oscillated light, the resulting output mode emits into regular single mode output because of the self-imaging effect of multimode interference. Furthermore, the semiconductor laser has a light output facet constituted by a facet of the multi-mode waveguide 2.