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:
Jul. 14, 1998
Filed:
Jan. 17, 1996
Yutaka Nagai, Tokyo, JP;
Akihiro Shima, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor laser includes a first conductivity type semiconductor substrate, a first conductivity type lower cladding layer, a quantum well structure active layer including alternately laminated barrier and well layers, a disordered region extending to laser resonator facets, a second conductivity type first upper cladding layer disposed on the quantum well structure active layer, a ridge structure disposed on the first cladding layer, and having a first region not proximate the laser resonator facets including a second conductivity type second upper cladding layer and a second conductivity type first contact layer and a second region, proximate a laser resonator facet having a first conductivity type first semiconductor layer of the same material and thickness as the second upper cladding layer and a first conductivity type second semiconductor layer of same material as the first contact layer, a first conductivity type current blocking layer having a band gap energy larger than that of the second upper cladding burying the ridge structure, and a second conductivity type second contact layer disposed on the current blocking layer and the ridge structure. The band gap energy at the laser resonator facets is larger than in other regions and serves as a window structure. A refractive index distribution in the transverse direction confines laser light in the transverse direction below the ridge structure and there is no astigmatism.