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AssigneeNippon Telegraph and Telephone Corporation
InventorsMakoto Yamada, Shinichi Aozasa, Tadashi Sakamoto, Atsushi Mori, Kouji Shikano, Makoto Shimizu
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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 level 3H6 to 3H5 excitation level. As a more preferable configuration, they improve the emission efficiency at 2.3 μm band by disclosing Tm-doped host glass.
A fiber laser using as a gain medium an optical fiber that has a core or a cladding doped with a rare-earth element having a laser transition level,
A spontaneous emission source using as a gain medium an optical fiber that has a core or a cladding doped with a rare-earth element having a laser transition level,
An optical fiber amplifier using as a gain medium an optical fiber that has a core or a cladding doped with a rare-earth element having a laser transition level,
Dependencies are inferred from the claim text.