Semiconductor laser and method of fabricating the same
AssigneesFujitsu Limited, The University of Tokyo
InventorsNobuaki Hatori, Tsuyoshi Yamamoto, Koji Otsubo, Yasuhiko Arakawa
Life of this patent
Estimating the term…
Abstract
An intrinsic GaAs waveguide layer is formed on a p-type AlGaAs cladding layer, a quantum dot active layer is formed further thereon. An n-type AlGaAs cladding layer is formed on the center portion of the quantum dot active layer. Thus-configured semiconductor laser is allowed to successfully suppress the area of the p-n junction plane to a small level, and to obtain a high level of reliability, because there is no need of processing the center portion of the quantum dot active layer, contributive to laser oscillation.
Claims17
A semiconductor laser comprising:
- a p-type first semiconductor layer;
- a second semiconductor layer formed above said first semiconductor layer, and having a band gap smaller than that of said first semiconductor layer;
- quantum dots formed above said second semiconductor layer, and having a band gap smaller than that of said second semiconductor layer;
- a third semiconductor layer formed above said quantum dots, and having a band gap larger than that of the quantum dots, conductivity type of at least one selected from the group consisting of said second semiconductor layer, said quantum dots and said third semiconductor layer being p-type;
- and
- an n-type fourth semiconductor layer selectively formed above said third semiconductor layer, and having a band gap larger than that of said third semiconductor layer.
A method of fabricating a semiconductor laser comprising the steps of:
- forming, above a p-type first semiconductor layer, a second semiconductor layer having a band gap smaller than that of said first semiconductor layer;
- forming, above said second semiconductor layer, quantum dots having a band gap smaller than that of said second semiconductor layer;
- forming, above said quantum dots, a third semiconductor layer having a band gap larger than that of said quantum dots, at least one selected from the group consisting of said second semiconductor layer, said quantum dots and said third semiconductor layer having a p-type conductivity;
- and
- selectively forming, above said third semiconductor layer, an n-type fourth semiconductor layer having a band gap larger than that of said third semiconductor layer.
Dependencies are inferred from the claim text.