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:
Jan. 17, 1984
Filed:
May. 05, 1981
Motohisa Hirao, Tokyo, JP;
Atsutoshi Doi, Ohme, JP;
Michiharu Nakamura, Hinodemachi, JP;
Shinji Tsuji, Kokubunji, JP;
Takao Mori, Hachioji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A buried-heterostructure semiconductor laser including a mesa-shaped optical confinement region having an active layer and a clad layer and disposed on a semiconductor substrate; a burying layer burying both side surfaces of the region; and at least one p-n junction so formed inside the burying layer in parallel to the active layer as to be brought under the reversely biased state during the operation of the laser; wherein surface protection semiconductor layers are formed on the mesa-shaped optical confinement region and on the burying layer, respectively, for protecting the semiconductor assembly in the arrangement such that these surface protection semiconductor layers do not come into direct contact with each other. Even if the forbidden band gas of these surface protection semiconductor layers are relatively small, it is possible to realize a semiconductor laser having an extremely small leakage current and reduced variance of threshold current values, while protecting the surface of the multi-layer semiconductor layers.