Nancy E Morris

US Patent:

56195230, Apr 8, 1997

Filed:

Sep 8, 1995

Appl. No.:

8/524956

Inventors:

John C. Connolly - Clarksburg NJ
Joseph H. Abeles - Highland Park NJ
Nancy A. Morris - Newtown PA

Assignee:

David Sarnoff Research Center, Inc. - Princeton NJ

International Classification:

H01S 318

US Classification:

372 96

Abstract:

A distributed-feed back semiconductor laser diode comprises a substrate of n-type conductivity GaAs having a pair of opposed surfaces, a pair of sides and a pair of ends. In sequence on one of the opposed surfaces are a first clad layer of n-type conductivity graded AlGaAs; a first confining layer of undoped AlGaAs; a first quantum well layer of undoped GaAs; a barrier layer of undoped AlGaAs; a second quantum well layer of undoped GaAs; a second confining layer of undoped AlGaAs; a spacer layer of p-type conductivity graded AlGaAs; a plurality of spaced, parallel grating bars of p-type conductivity AlGaAs extending across the spacer layer parallel to the ends of the substrate; a second clad layer of p-type conductivity graded AlGaAs over and between the grating bars; and contact layer of p+ type conductivity GaAs. A first conductive contact layer contacts the contact layer and a second conductive contact layer is on the other opposed surface of the substrate. The dual quantum well layers of undoped GaAs provide a laser diode which emits visible radiation at a wavelength less than 880 nm.