We present mid-IR spectroscopic characterization of the low-phonon chalcogenide glass, Ga2Ge5S13(GGS) doped with Er3+ions. Under the excitation at ∼800 nm, Er3+:GGS exhibited broad mid-IR emission bands centered at ∼2.7, ∼3.5, and ∼4.5 µm at room temperature. The emission lifetime of the4I9/2level of Er3+ions in GGS glass was found to be millisecond-long at room temperature. The measured fluorescence lifetimes were nearly independent of temperature, indicating negligibly small nonradiative decay rate for the4I9/2state, as can be expected for a low-maximum-phonon energy host. The transition line-strengths, radiative lifetimes, fluorescence branching ratios were calculated by using the Judd-Ofelt method. The peak stimulated emission cross-section of the4I9/2→4I11/2transition of Er3+ion was determined to be ∼0.10×10−20cm2at room temperature.
A comparative study was conducted to investigate the 3.9 µm mid-IR emission properties of Ho3+doped NaYF4and CsCdCl3crystals as well as Ho3+doped Ga2Ge5S13glass. Following optical excitation at ∼890 nm, all the studied materials exhibited broad mid-IR emissions centered at ∼3.9 µm at room temperature. The mid-IR emission at 3.9 µm, originating from the5I5→5I6transition, showed long emission lifetime values of ∼16.5 ms and ∼1.61 ms for Ho3+doped CsCdCl3crystal and Ga2Ge5S13glass, respectively. Conversely, the Ho3+doped NaYF4crystal exhibited a relatively short lifetime of ∼120 µs. Temperature dependent decay time measurements were performed for the5I5excited state for all three samples. The results showed that the emission lifetimes of Ho3+:CsCdCl3and Ho3+:Ga2Ge5S13were nearly temperature independent over the range studied, while significant emission quenching of the5I5level was observed in Ho3+:NaYF4. The temperature dependence of the multi-phonon relaxation rate for 3.9 µm mid-IR emission in Ho3+:NaYF4crystal was determined. The room temperature stimulated emission cross-sections for all three samples were calculated using the Füchtbauer-Landenburg equation. Furthermore, the results of Judd-Ofelt analysis are presented and discussed.
more » « less- Award ID(s):
- 1827820
- NSF-PAR ID:
- 10407506
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optical Materials Express
- Volume:
- 13
- Issue:
- 5
- ISSN:
- 2159-3930
- Page Range / eLocation ID:
- Article No. 1307
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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The mid-IR spectroscopic properties of
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We present mid-IR spectroscopic characterization of the low-phonon chalcogenide glass, Ga2Ge5S13 (GGS) doped with Er3+ ions. Under the excitation at ∼800 nm, Er3+:GGS exhibited broad mid-IR emission bands centered at ∼2.7, ∼3.5, and ∼4.5 µm at room temperature. The emission lifetime of the 4I9/2 level of Er3+ ions in GGS glass was found to be millisecond-long at room temperature. The measured fluorescence lifetimes were nearly independent of temperature, indicating negligibly small nonradiative decay rate for the 4I9/2 state, as can be expected for a low-maximum-phonon energy host. The transition line-strengths, radiative lifetimes, fluorescence branching ratios were calculated by using the Judd-Ofelt method. The peak stimulated emission cross-section of the 4I9/2 → 4I11/2 transition of Er3+ ion was determined to be ∼0.10×10−20 cm2 at room temperature.more » « less