The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 05, 2011
Filed:
Mar. 14, 2008
Naofumi Suzuki, Tokyo, JP;
Masayoshi Tsuji, Tokyo, JP;
Takayoshi Anan, Tokyo, JP;
Kenichiro Yashiki, Tokyo, JP;
Hiroshi Hatakeyama, Tokyo, JP;
Kimiyoshi Fukatsu, Tokyo, JP;
Takeshi Akagawa, Tokyo, JP;
Naofumi Suzuki, Tokyo, JP;
Masayoshi Tsuji, Tokyo, JP;
Takayoshi Anan, Tokyo, JP;
Kenichiro Yashiki, Tokyo, JP;
Hiroshi Hatakeyama, Tokyo, JP;
Kimiyoshi Fukatsu, Tokyo, JP;
Takeshi Akagawa, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
The present invention provides a surface-emission type semiconductor laser wherein an effective length of a cavity is reduced, thereby enabling to realize a higher-speed direct modulation. In the surface-emission type semiconductor laser according to the present invention, when supposing the optical path length (L) of a resonator part relative to a lasing wavelength λto be given as 0.9×λ≦L≦1.1×λ, and denoting the refractive indexes of a high refractive index layer and a low refractive index layer of a dielectric DBR by nand n; the average refractive index within an optical path length λ/4 in the semiconductor in contact with the dielectric DBR by n; and the refractive indexes of the high refractive index layer and the low refractive index layer of a semiconductor DBR by nand n, respective materials to be used are selected so as to satisfy the following conditions (1) and (2):()()(),  (1)