Krefting Dagmar, Mettin Robert, Lauterborn Werner
Drittes Physikalisches Institut, Universität Göttingen, Germany.
J Acoust Soc Am. 2002 Nov;112(5 Pt 1):1918-27. doi: 10.1121/1.1509427.
Sonoluminescing single bubbles driven simultaneously by two harmonic frequencies were recently reported to increase the maximum light output up to a factor of 3 with respect to single mode excitation. In this paper, experimental and numerical results on single-bubble sonoluminescence (SBSL) in an air/water system using the fundamental mode of 25 kHz and the second harmonic at 50 kHz are presented. The region of light emission is mapped in the three-dimensional parameter space spanned by the two driving pressure amplitudes and their relative phase. Good agreement was seen between measured light output, maximum bubble radius, and stability boundaries and the numerical model which is based on spherical bubble oscillations regarding diffusive and shape stability. The maximum brightness was enhanced by a factor up to 2.5 with respect to single mode SBSL. However, long-term measurements reveal great variation of the emission at fundamental mode driven SBSL and of the boost factor reached with two frequencies. The overall brightness maxima of both excitation methods within a period of several hours turn out to show little difference.
最近有报道称，由两个谐波频率同时驱动的声致发光单气泡，相对于单模激发，其最大光输出增加了两倍。本文给出了在空气/水系统中使用25kHz基模和50kHz二次谐波进行单气泡声致发光（SBSL）的实验和数值结果。发光区域在由两个驱动压力振幅及其相对相位所构成的三维参数空间中进行了映射。实测光输出、最大气泡半径和稳定性边界与基于球形气泡扩散和形状稳定性振荡的数值模型之间取得了良好的一致性。相对于单模SBSL，最大亮度提高了2.5倍。然而，长期测量结果表明，基模驱动的SBSL发射以及双频驱动所达到的增强因子存在很大变化。在几个小时的时间段内，两种激发方法的整体亮度最大值几乎没有差异。
