QUANTUM EFFICIENCY AND EXCITED-STATE RELAXATION DYNAMICS IN NEODYMIUM-DOPED PHOSPHATE LASER GLASSES
QUANTUM EFFICIENCY AND EXCITED-STATE RELAXATION DYNAMICS IN NEODYMIUM-DOPED PHOSPHATE LASER GLASSES
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DOI：
10.1364/josab.8.001391
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发表时间：
1991-07-01
影响因子：
1.9
通讯作者：
STAVER, PR
中科院分区：
文献类型：
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作者：
CAIRD, JA;RAMPONI, AJ;STAVER, PR
采用积分球检测系统的辐射校准光谱技术已被用来确定两个市售的掺钕磷酸盐激光玻璃，LG-750和LG-760的荧光量子效率。 量子效率和荧光寿命进行了测量样品与各种钕浓度。 结果表明，浓度猝灭的影响时，准确地描述共振非辐射激发跳跃（Burshtein模型）和湮灭交叉弛豫占福斯特-德克斯特偶极-偶极能量转移理论。 在这些玻璃中，发现非辐射激发跳跃的Forster-Dexter临界范围为R（DD）= 11埃，而交叉弛豫的临界范围接近R（DA）= 4埃。 在低浓度的Nd 3+的量子效率为（92 +/- 5）%，这意味着一个非辐射弛豫率为210 +/- 150 s-1的孤立离子。 这些玻璃的辐射寿命和受激发射截面的改进值也推导出从测量。
Radiometrically calibrated spectroscopic techniques employing an integrating-sphere detection system have been used to determine the fluorescence quantum efficiencies for two commercially available Nd3+-doped phosphate laser glasses, LG-750 and LG-760. Quantum efficiencies and fluorescence lifetimes were measured for samples with various neodymium concentrations. It is shown that the effects of concentration quenching are accurately described when both resonant nonradiative excitation hopping (the Burshtein model) and annihilation by cross relaxation are accounted for by Foster-Dexter dipole-dipole energy-transfer theory. The Forster-Dexter critical range for nonradiative excitation hopping was found to be R(DD) = 11 angstrom, while the critical range for cross relaxation was close to R(DA) = 4 angstrom in these glasses. The quantum efficiency at low Nd3+ concentrations was (92 +/- 5)%, implying a nonradiative relaxation rate of 210 +/- 150 s-1 for isolated ions. Improved values for the radiative lifetimes and the stimulated emission cross sections for these glasses were also deduced from the measurements.