| 摘要 |
PURPOSE:To inject a current efficiently into an active region so as to improve a device in properties such as an optical output, a response speed, and others by a method wherein a region of a current blocking layer adjacent to a clad layer is composed of a semiconductor layer whose forbidden band width is equal to that of the clad layer. CONSTITUTION:An n-type InP current blocking layer 5 which has the same forbidden band width as that of a clad layer 4 is provided on a junction part of the blocking layer 5 with the p-type InP upper clad layer 4. Therefore, the width difference of the forbidden band at the junction part is eliminated, so that even if almost the same current as a conventional device is made to flow through the p-type InP upper clad layer 4 which corresponds to a gate section of a parasitic thyristor, the thyristor section becomes hard to turn on by the extent induced by the elimination of the width difference. By these processes, a current is efficiently injected into an active layer and the intensity distribution of an emitted optical output is made almost equal to the diameter of a stripe window 11, so that the coupling between the emitted light rays and an optical fiber is improved in efficiency. And, current is uniformly converted into light and a device is also improved in a response speed property. |
