Semiconductor laser, semiconductor optical amplifier, and production method thereof

摘要

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 is provided. The semiconductor laser has a single mode waveguide and a multi-mode waveguide. The multi-mode waveguide has a wider width than that of the single mode waveguide. The single mode waveguide provides a single mode to an oscillated light oscillated from an active light waveguide. While the multi-mode waveguide 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. Further more, the semiconductor laser has a light output end constituted by an end of the multi-mode waveguide.