| US 7,522,647 B2 | ||
| Semiconductor laser and method of fabricating the same | ||
| Nobuaki Hatori, Kawasaki (Japan); Tsuyoshi Yamamoto, Kawasaki (Japan); Koji Otsubo, Kawasaki (Japan); and Yasuhiko Arakawa, Kanagawa (Japan) | ||
| Assigned to Fujitsu Limited, Kawasaki (Japan); and The University of Tokyo, Tokyo (Japan) | ||
| Filed on Jan. 30, 2006, as Appl. No. 11/341,588. | ||
| Claims priority of application No. 2005-104448 (JP), filed on Mar. 31, 2005. | ||
| Prior Publication US 2006/0222028 A1, Oct. 05, 2006 | ||
| Int. Cl. H01S 5/00 (2006.01) | ||
| U.S. Cl. 372—45.01 [372/43.01; 372/44.01; 372/66; 372/68; 257/14; 257/22; 257/103] | 17 Claims |
| 1. A semiconductor laser comprising:
a p-type cladding layer;
a second semiconductor layer formed above said p-type cladding layer, and having a band gap smaller than that of said p-type
cladding layer;
a p-type quantum dot active layer formed above said second semiconductor layer and including:
a plurality of layers which have quantum dots having a band gap smaller than that of said second semiconductor layer; and
a plurality of p-type or intrinsic third semiconductor layers formed above said layers which have 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 at least either one of
said quantum dots and said third semiconductor layer having p-type conductivity,
wherein each of said layers which have quantum dots and each of said third semiconductor layers are alternated in said p-type
quantum dot active layer; and
an n-type cladding layer selectively formed on said quantum dot active layer, and having a band gap larger than that of said
third semiconductor layer, there being a pin-junction interface between said n-type cladding layer and said quantum dot active
layer,
wherein an area of said pin-junction interface is smaller than an area of an interface between said second semiconductor layer
and said quantum dot active layer.
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