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:
Dec. 17, 1991
Filed:
Jun. 07, 1990
Applicant:
Inventors:
Kazuhisa Uomi, Hachioji, JP;
Tsukuru Ohtoshi, Kokubunji, JP;
Tomonobu Tsuchiya, Kodaira, JP;
Shinji Sasaki, Komoro, JP;
Naoki Chinone, Chofu, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01S / ;
U.S. Cl.
CPC ...
372 45 ; 372 46 ; 372 26 ; 372 28 ;
Abstract
A semiconductor laser device of the field modulation type includes a structure in which the threshold carrier density for laser oscillation is reduced so as to enable an effective action of a modulated electric field applied externally on an active region for radiating light, thereby enabling an extremely high speed modulation. A quantum structure which does not fulfill the charge neutrality condition for free-carriers or a strained super lattice structure is adopted as the structure in which the threshold carrier density is reduced.