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. 25, 2000
Filed:
Feb. 09, 1998
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor laser includes a first conductivity type semiconductor substrate having a gain region and a spot size changing region adjacent each other; a first conductivity type lower cladding layer disposed on the substrate; an active layer disposed on the lower cladding layer and having a thickness which is uniform in the gain region and gradually decreases in the spot size changing region with distance from the gain region; a second conductivity type upper cladding layer disposed on the active layer and having a stripe-shaped ridge, the ridge extending along the gain region and the spot size changing region; a first electrode disposed on the ridge of the upper cladding layer; and a second electrode disposed on a rear surface of the substrate. Current flow is concentrated in the ridge of the upper cladding layer. Further, when the ridge is fabricated, portions of the active layer in which a current will be injected during operation of the laser are not exposed to the atmosphere and not oxidized, resulting in a highly reliable semiconductor laser with an integrated spot size changing part and gain part.