Efficient O-band emission from Pr 3+ doped low phonon energy ZnF 2 -based glasses

Pr 3+ doped ZnF 2 -based (ZnF 2 -BaF 2 -SrF 2 -YF 3 ) glasses with a low phonon energy of ∼420 cm −1 are prepared by using a conventional melt-quenching method in dry N 2 atmosphere. Under the excitation of a 980 nm laser diode, intense emission at ∼1310 nm is observed from the Pr 3+ doped ZnF 2 -based glasses. The full spectral width at half maximum is 107 nm (1275–1382 nm), which is ∼7 nm wider than that of Pr 3+ doped ZrF 4 -based glass (∼100 nm, 1279–1379 nm). The measured lifetime (∼183 μs) of the excited energy level 1 G 4 for Pr 3+ ions in the ZnF 2 -based glass is also much longer than that of Pr 3+ doped in ZrF 4 -based glass (∼110 μs). According to the theoretically calculated results, a positive gain of 31.7 dB at 1304 nm can be obtained from O-band optical amplifiers based on the Pr 3+ doped ZnF 2 -based glass, which is 5 dB higher than that obtained from amplifiers based on Pr 3+ doped ZrF 4 -based glass with a same pump condition. The corresponding bandwidth for a net gain of >20 dB is ∼51 nm (1277–1328 nm), and the noise figure is calculated to be < 5.8 dB in above spectral range. Our results indicate that Pr 3+ doped ZnF 2 -based glasses have the potential for constructing efficient O-band optical amplifiers.