We report an experimental study of nonlinear radiation trapping in a high-density rubidium vapor where the self-broadening of the resonance transitions $5S_{1/2}-5P_{3/2}$ exceeded the Doppler broadening. The atomic number densities used were $N_1=3\times {10}^{16}$ cm${}^{-3}$ and $N_2=8\times {10}^{16}$ cm${}^{-3}$. In our experiment, a signal of retro-fluorescence was recorded. By means of scanning a single mode laser near the resonance transition, spectral dependence of the effective radiative lifetime was measured with different values of the excitation optical power. Growth of the effective radiative lifetime with increasing power was observed. Within the framework of a simple model, it was shown that incoherent optical saturation can be increased by the number of photon absorption-reemission in the radiation transfer process. Further experiments are suggested.

我们报告了对高密度rub蒸气中非线性辐射俘获的实验研究，其中共振跃迁的自扩展 $5{\mathrm{小号}}_{\mathrm{1个}/2}-5P_{3/2}$超出了多普勒范围。使用的原子序数密度为${ñ}_{\mathrm{1个}}=3\times {10}^{16}$ 厘米${}^{-3}$ 和 ${ñ}_2=8\times {10}^{16}$ 厘米${}^{-3}$。在我们的实验中，记录了逆荧光信号。通过在共振跃迁附近扫描单模激光器，可以用不同的激发光功率值测量有效辐射寿命的光谱依赖性。观察到有效辐射寿命随着功率的增加而增长。在一个简单模型的框架内，研究表明，通过辐射传输过程中光子吸收-释放的数量，可以增加非相干光饱和度。建议进一步的实验。