The features of fluorescence emission in a dye-doped dense multiple scattered medium under pulsed laser pumping are considered in terms of confined excitation in small zones associated with laser speckles occurring in a pumped medium. The results of numerical modeling of the fluorescence emission kinetics are compared to the experimental data obtained using the rhodamine 6G-doped layers of the densely packed TiO₂ (anatase) particles pumped at 532 nm by 10 ns laser pulses. The intensity of pump radiation during the action of laser pulses was varied from 1·10⁵ W/cm² to 5·10⁷ W/cm². In the recovery of the ratios of stimulated to a spontaneous emission, the spectra of the stimulated component were fitted using the spectral function derived by R. Dicke. In the framework of the considered concept, saturation of the ratio of the stimulated to a spontaneous emission and linear growth of an integrated fluorescence output with a practically unchangeable half-width of the emission spectra at high pump intensities are interpreted.

中文翻译：

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抽运激光的斑点图案是致密随机介质中受激荧光发射的限制因素

考虑到在与泵浦介质中发生的激光斑点相关的小区域内的受限激发，可以考虑在脉冲激光泵浦条件下的染料掺杂的致密多重散射介质中的荧光发射特征。将荧光发射动力学数值模拟的结果与使用罗丹明6G掺杂层，通过10 ns激光脉冲在532 nm泵浦的密集堆积的TiO ₂（锐钛矿）颗粒的实验数据进行比较。激光脉冲作用期间泵浦辐射的强度在1·10 ⁵ W / cm ²到5·10 ⁷ W / cm ^{2之间变化}。在恢复受激发射与自发发射的比率时，使用R. Dicke推导的光谱函数拟合受激成分的光谱。在所考虑的概念的框架中，解释了在高泵浦强度下，激发光与自发发射之比的饱和度和积分荧光输出的线性增长以及发射光谱的几乎不变的半宽度。