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:
May. 28, 1991
Filed:
Nov. 06, 1989
Kunihiko Isshiki, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A multi-quantum well laser having a self-aligned structure which limits catastophic optical damage by producing window regions near the facets without significantly decreasing the efficiency of the laser. The semiconductor laser includes at least a first conductivity type lower cladding layer, an active layer including a multi-quantum well structure, a second conductivity type first upper cladding layer, a first conductivity type current blocking layer, and a second conductivity type second upper cladding layer successively disposed on a first conductivity type semiconductor substrate. The current blocking layer has a central elongate stripe shaped current confinement groove extending between the laser facets which stabilizes the transverse mode and confines current to a channel-like region in the active layer. First conductivity type dopant impurities form disordering regions located adjacent the facets which invade and disorder the multi-quantum well active layer to create disordered active layer regions. Second conductivity type dopant impurities form separating regions located adjacent the faects which separate the current blocking layer and the disordering regions to prevent current leakage between the current blocking layer and the disordering regions.