| 摘要 |
PURPOSE:To stabilize transverse mode with low threshold value, by constituting a central part of active regions among clad layers adjacent to the active regions of semiconductor layers with high refractive indexes and the periphery thereof of those with low ones. CONSTITUTION:Among the clad layers adjacent to the active region 7, layers on an N-InP semiconductor substrate 8 side are constituted of two parts the first semiconductor layer 9 of N-InP and second one 10 of P-InP. In general, in III-V group compound semiconductors of InP, etc., P types of conductivity types have refractive indexes some higher than those of N types. Therefore, in the central part of the active region 7, clad layers are constituted of a layer 10 with high refractive index. On the other hand, in the periphery separated from the region 7, they are constituted of the layers 10 and 9. As the result, the central part of the active region 7 has high effective refractive index with the width L with laser light stabilized to exist in the active region 7. |
