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:
Mar. 31, 2015
Filed:
Mar. 08, 2013
Kei Hara, Tokyo, JP;
Kei Hara, Tokyo, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A semiconductor stack includes a semiconductor DBR (Distributed Bragg Reflector) formed on a substrate, and a resonator formed on the semiconductor DBR laminating wide-band semiconductor layers and active layers alternately. Each of the active layers includes MQWs (Multiple Quantum Wells) and two spacer layers formed one on each surface of the MQWs. The MQWs are formed by laminating barrier layers and quantum well layers alternately. There are n layers of the wide-band semiconductor layer formed, and a band gap Egof an m-th wide-band semiconductor layer counting from the substrate and a band gap Egof an m−1-th wide-band semiconductor layer counting from the substrate satisfy Eg<Egwhere n and m are integers greater than or equal to 2, and 1<m≦n.