Characterization of spontaneous and stimulated emission from praseodymium (Pr/sup 3+/) ions doped into a silica-based monomode optical fiber

The fluorescence spectrum of praseodymium in a silica host has been investigated through the direct excitation of the /sup 3/P/sub 0/, /sup 1/D/sub 2/, and 1G/sub 4/ absorption bands, which occur at around 488, 590, and 974 nm, respectively. The observed spontaneous emission consists of four main bands with peaks at 633, 707, 888, and 1080 nm. In each case the level principally responsible for these emissions was found to be 1D/sub 2/. Stimulated emission has been seen for the first time at 888 nm for a threshold of 10 mW absorbed power. In addition, the lasing characteristics at 1080 nm have been investigated.<
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