| 摘要 |
PURPOSE:To obtain a semiconductor laser of dynamic single mode which can be readily fed back at diffraction grating with ready manufacture by disposing a diffraction grating region having large equal refractive index near an active region in parallel. CONSTITUTION:A diffraction grating region 102A in a plurality of epitaxial region has larger equal refractive index than an active region 105. For example, the region 102A is used as an InGaAsP epitaxial region, and has smaller forbidden band width and larger equal refractive index than the region 105. The shape of the grating formed on the region 102A is such that wavy grooves are aligned at the prescribed interval in a direction perpendicular to the longitudinal direction of the region 105. Thus, since the region 102A once inputs a light from the region 105 due to the refractive index, reflects the light of only prescribed wavelength by the operation of the grating therein and again returns only the light to the region 105, a laser oscillation of single mode is generated in the region 105. |
