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:
Mar. 26, 1991
Filed:
Jul. 12, 1989
Shigeru Mitsui, Itami, JP;
Ryo Hattori, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor laser particularly adapted for operation in the self-pulsation mode and method for production thereof. A central mesa is formed in the upper cladding layer and normally requires relatively thick sections at either side of the mesa in order to form a waveguide of sufficient thickness to cause self-pulsation operation. In order to control the thickness of the upper cladding layer bounding the mesa, the mesa is first formed by etching the regions bounding the mesa to relatively thin sections capable of ready gauging by optical interferometry. A composite upper cladding layer is then formed by utilizing MOCVD crystal growth techniques to form a buffer layer on the upper cladding layer bounding the mesa, the buffer layer having an aluminum content about the same as the aluminum content of the AlGaAs upper cladding layer. The composite layer functions as a comparatively thick waveguide which can be formed to the necessary thickness with adequate accuracy to provide a high yield when producing self-pulsation lasers according to the present invention.