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:
Feb. 12, 2013
Filed:
Feb. 24, 2009
Masamichi Yamanishi, Hamamatsu, JP;
Kazuue Fujita, Hamamatsu, JP;
Tadataka Edamura, Hamamatsu, JP;
Naota Akikusa, Hamamatsu, JP;
Masamichi Yamanishi, Hamamatsu, JP;
Kazuue Fujita, Hamamatsu, JP;
Tadataka Edamura, Hamamatsu, JP;
Naota Akikusa, Hamamatsu, JP;
Hamamatsu Photonics K.K., Hamamatsu-shi, Shizuoka, JP;
Abstract
A quantum cascade laser is configured so as to include a semiconductor substrate and an active layer which is provided on the substrate and has a cascade structure including multistage-laminated unit laminate structures each including a quantum well emission layer and an injection layer. Moreover, the unit laminate structure has, in its subband level structure, an emission upper level, a lower level, and an injection levelof higher energy than the upper level, and light hν is generated by intersubband transition of electrons from the level to the level in the emission layer, and electrons after emission transition are injected into the injection levelof the subsequent stage via the injection layer. In addition, the emission layer includes two or more well layers, and the first well layer closest to the injection layer of the preceding stage is used as a well layer for injection level formation.