In this work, we studied stimulated hyper-Raman scattering in the spectral range near the second optical harmonic of a laser pump in water samples containing gas nanobubbles (bubstons). The spectrum of the hyper-Raman scattering from nanobubble-free water samples was found to differ from that of nanobubbles containing water samples. To interpret these results, we put forward a hypothesis that the detected effect is related to the huge enhancement caused by the generation of a resonance surface plasmon inside a gas nanobubble during optical (laser-induced) breakdown. The plasmon bandwidth $\Delta \omega$ was theoretically estimated. It turned out that $\Delta \omega \approx {\omega _0}$, where ${\omega _0}$ is the resonant plasmon frequency, i.e., in our case, the quality factor of the plasmon oscillator is very low. The estimate of the enhancement factor, which was made based on experimental data, gives $\approx 1.5 \times {{10}^{15}}$.

中文翻译：

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气体纳米气泡在水中光的非线性超拉曼散射中的作用

在这项工作中，我们研究了在含有气体纳米气泡（气泡）的水样中，激光泵的二次光谐波附近光谱范围内的受激超拉曼散射。发现来自无纳米气泡的水样品的超拉曼散射的光谱不同于含有水样品的纳米气泡的光谱。为了解释这些结果，我们提出一个假设，即检测到的效果与光学（激光诱导）击穿过程中气体纳米气泡内部共振表面等离子体激元的产生所引起的巨大增强有关。理论上估计了等离激元带宽$ \ Delta \ omega $。原来$ \ Delta \ omega \ approx {\ omega _0} $，其中$ {\ omega _0} $是共振等离子体激元频率，即在我们的情况下，等离子体激元振荡器的品质因数非常低。增强因子的估计是根据实验数据得出的，约为$ 1.5乘以{{10} ^ {15}} $。