| Autor: |
Nostrand, M. C., Page, R. H., Payne, S. A., Isaenko, L. I., Yelisseyev, A. P. |
| Zdroj: |
Journal of the Optical Society of America B: Optical Physics; March 2001, Vol. 18 Issue: 3 p264-276, 13p |
| Abstrakt: |
Optical properties including radiative quantum efficiencies, cross-relaxation coefficients, refractive index, energy-gap law parameters, and maximum phonon energy are presented for a new low-phonon-frequency, nonhygroscopic host crystal potassium lead chloride (KPb_2Cl_5) doped with Dy^3+ and Nd^3+. Assuming that the total decay rate (W) from each level is composed of radiative (A^rad), multiphonon (W^MP), and concentration-dependent cross-relaxation (W^c) rates (W=A^rad+W^MP+W^c), we determined radiative quantum efficiencies (η^rad=A^rad/W) from emission data for five samples of various Dy^3+ concentrations (N_0). These results were compared with values calculated from a Judd–Ofelt analysis of the absorption spectrum. This technique required identification of cross-relaxation pathways. A cross-relaxation coefficient k=1.83×10^−37 cm^6 s^−1 (where W^c=kN_0^2) was measured for the Dy^3+ ^6H_9/2+^6F_11/2 level. The measured multiphonon decay rates yielded energy-gap law (W^MP[ΔE]≈B exp[−βΔE]) parameters B=3.72×10^9 s^−1 and β=1.16×?10^−2 cm, indicating that laser action should be possible to near 9 μm (ΔE=1100 cm^−1) in this laser host at room temperature. |
| Databáze: |
Supplemental Index |
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