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:
Aug. 09, 2011
Filed:
Mar. 18, 2010
Chie Fukuda, Yokohama, JP;
Chie Fukuda, Yokohama, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
A wavelength tunable laser according to the present invention includes a first facet and a second facet opposite the first facet, a reflective region provided adjacent to the second facet, and a gain region provided between the first facet and the reflective region. The reflective region has a plurality of reflection peak wavelengths that periodically vary at a predetermined wavelength interval. The first facet and the reflective region constitute a laser cavity. Furthermore, the gain region includes an active layer where light is generated, a diffraction grating layer having a diffraction grating whose grating pitch varies in a light propagation direction, a refractive-index control layer provided between the active layer and the diffraction grating layer, a first electrode for injecting current into the active layer, and a plurality of second electrodes arranged in the light propagation direction to inject current into the refractive-index control layer.