Buried heterostructure semiconductor laser fabricated on a p-type substrate

摘要

A buried heterostructure semiconductor laser formed on a substrate having a first semiconductor of p-type conductivity has a mesa- striped active layer region having a height extending from a first p-type semiconductor layer at the foot of the mesa to a n-type cladding layer on the top of the mesa. On both sides of the mesa-striped region, a second p- type semiconductor layer, a first n-type semiconductor layer, a third p- type semiconductor layer, and a second semiconductor layer having a band gap smaller than that of the other layers except the active layer are sequentially formed from the substrate side. Additionally, the entire structure is further buried with a n-type semiconductor layer. The second semiconductor layer may be inserted in between the second p-type semiconductor layer and the first n-type semiconductor layer as well. Furthermore, the second semiconductor layer may be of a semiconductor material with lower carrier concentration doping than the other layers except the active layer, which is usually undoped. In an alternative configuration, the two sides of the mesa structure may form a channel into which the aforementioned layers will be buried.