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:
Dec. 25, 2007
Filed:
Jul. 27, 2004
Makoto Yamada, Tokyo, JP;
Shinichi Aozasa, Atsugi, JP;
Tadashi Sakamoto, Atsugi, JP;
Atsushi Mori, Atsugi, JP;
Kouji Shikano, Hakodate, JP;
Makoto Shimizu, Mito, JP;
Makoto Yamada, Tokyo, JP;
Shinichi Aozasa, Atsugi, JP;
Tadashi Sakamoto, Atsugi, JP;
Atsushi Mori, Atsugi, JP;
Kouji Shikano, Hakodate, JP;
Makoto Shimizu, Mito, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
New fiber lasers, spontaneous emission sources, and optical fiber amplifiers are provided. Their conventional counterparts, which have a fiber doped with thulium (Tm) ions and excited by 0.67 μm or 0.8 μm pumping light, have a problem in that their characteristics are deteriorated with the elapse of time. The new fiber lasers, spontaneous emission sources, and optical fiber amplifiers use 1.2 μm light as pumping light. Alternatively, they use a pumping source for exciting the thulium from the lowest energy levelHtoHexcitation level. As a more preferable configuration, they improve the emission efficiency at 2.3 μm band by disclosing Tm-doped host glass.