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:
Sep. 01, 1989
Yuji Abe, Amagasaki, JP;
Hiroshi Sugimoto, Amagasaki, JP;
Kenichi Ohtsuka, Amagasaki, JP;
Toshiyuki Oishi, Amagasaki, JP;
Teruhito Matsui, Amagasaki, JP;
Abstract
A semiconductor laser device includes an active layer, a first semiconductor layer having a larger energy band gap than the active layer, a diffraction grating layer having a larger energy band gap than the active layer and a smaller energy band gap than the first semiconductor layer, and a second semiconductor layer having the same composition as the first semiconductor layer, successively grown on the active layer, parallel stripe grooves of predetermined period reaching the first semiconductor layer produced at the entire surface of the grown layers, a cladding layer having the same composition as the first semiconductor layer which is re-grown thereon, and a diffraction grating constituted by the remainder of the diffraction grating layer. The coupling coefficient of the light is determined by the film thickness of a layer produced between the active layer and the diffraction grating layer, and the amplitude of the diffraction grating is determined by the layer thickness of the diffraction grating layer. Therefore, the coupling coefficient can be set at a design value at high precision and at high reproducibility.