| 摘要 |
PURPOSE:To improve on the coupling efficiency by a method wherein a stripe- geometry trench is provided to run through a semi-insulating substrate and is filled up with a contact layer, upper and lower clad layers, and an active layer. CONSTITUTION:A stripe-geometry trench is provided to run through a semi- insulating substrate 1. The trench is so constructed that a p-type contact layer 5, a P-type clad layer 4, an active layer 3, and an n-type clad layer 2 are placed therein, in that order. The entirety of the active layer 3 buried in this way in the trench serves as an active region 11. Accordingly, with the current density distribution being uniform throughout the active region 11, a higher couple efficiency is attained. |
