| 摘要 |
PURPOSE:To prevent light from returning an active part and to eliminate axis misalignment when fibers are coupled by increasing the width of an active layer in a taper shape nearby one or both of two end surfaces and forming reflection preventive films on both end surfaces. CONSTITUTION:A light guide layer 2, the active layer 3, a clad layer 4 and an electrode layer 5 are grown on a substrate 1. The element is formed in the taper shape in an input-side taper waveguide area 11. Then, the respective layers 2 - 5 are etched until they reach the substrate 1 to form a laminate body in a reverse mesa shape. Then a p type InP layer 6 and an n type InP layer 7 are grown by current narrowing-down embedding as 2nd growth at the part removed by the etching. On the entire top surface, an electrode 8 is formed, an n type ohmic electrode 12 is formed, and then the reflection preventive multi-layered films 13 and 14 are formed. Consequently, the films 13 and 14 are vapor-deposited on condition that the reflection factor of the end surfaces is 0.5% to obtain about 20dB element gain. |
