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. 18, 2014
Filed:
May. 18, 2010
Kazuue Fujita, Hamamatsu, JP;
Masamichi Yamanishi, Hamamatsu, JP;
Tadataka Edamura, Hamamatsu, JP;
Naota Akikusa, Hamamatsu, JP;
Kazuue Fujita, Hamamatsu, JP;
Masamichi Yamanishi, 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 to include a semiconductor substrate and an active layer which is provided on the substrate and has a cascade structure formed by multistage-laminating unit laminate structureseach including an emission layerand an injection layer. The unit laminate structurehas, in its subband level structure, a first emission upper level L, a second emission upper level Lof an energy higher than the first emission upper level, an emission lower level L, and a relaxation level Lof an energy lower than the emission lower level, light is generated by intersubband transitions of electrons from the first and second upper levels to the lower level, and electrons after the intersubband transitions are relaxed from the lower level to the relaxation level and injected from the injection layerinto an emission layerof a subsequent stage via the relaxation level. Accordingly, a quantum cascade laser capable of preferably obtaining emission in a broad wavelength range is realized.