Pumped by 514.5 nm Ar ion laser, superfluorescence was observed in a 3 m Nd-doped silica fiber. The maximum output power is 6 mW with the emission linewidth-of 3 nm. A good agreement is found between experimental; data and theoretical fits.
A detailed investigation is made of the spectral properties of several superfluorescence operations in Nd-doped and Er-doped silica fibres pumped by a 514.5 nm Ar ion laser. The study demonstrates the spectral narrowing processes in the operations of superfluorescence. In Nd-doped fibre, the higher gain at 1080 nm suppresses the emission at about 910 nm, but the authors have still realized, for the first time, superfluorescence in this wavelength band, and a 0.4 mW output was achieved in a double-pass configuration. Also, the process of change from superfluorescence to lasing was recorded and analysed.
The inhomogeneous behavior of the 1.06 /spl mu/m-neodymium transitions in doped optical fibers have been investigated, using the fluorescence line narrowing technique, pumping on the /sup 4/F/sub 3/2/ and /sup 4/F/sub 5/2/ sublevels at 4 K. Each observed transition has been identified. As the pump wavelength varies, the shift of the main fluorescence line is 40 nm, with the two pumping levels. We have studied the spectral behavior of the superfluorescence as a function of the pump wavelength, the temperature, and the absorbed power. The spectral evolution depends on /spl lambda//sub p/ with 19 nm-tuning range at low temperature. At 300 K, the quasihomogeneous behavior of the transition decreases the tunability to 14 nm. Based on these results, we present a simple technique permitting precise prediction of gain and spectral line shapes of superfluorescent Nd-doped fiber sources.>
A stimulated-Raman-gain medium at 1.56-microm wavelength, consisting of molecular deuterium dissolved in low-loss silica optical fiber and pumped by 1.06-microm Nd:YAG laser light, is described. In a 100-m-long fiber with pump power of 130 W, InGaAsP injection-laser probe light at 1.56 microm was amplified by a factor of 4000 to an output power of 150 mW. The measured stimulated-Raman-gain coefficient at 1.56 microm is 7 x 10(-12) cm/W, about equal to the Raman gain of SiO(2) at the same wavelength.