Scattering of Light by Thermal Ripplons
Scattering of Light by Thermal Ripplons
复制标题
热波纹引起的光散射
DOI：
10.1103/physrevlett.20.248
复制
发表时间：
1968
影响因子：
8.6
通讯作者：
U. Ingard
中科院分区：
文献类型：
--
作者：
R. Katyl;U. Ingard
空间光波长，8是从地表以下入射的光束的极角。表面振动受到粘性的抑制，双重线的线形为洛伦兹形，半强度宽度A~=2/T，其中T可视为涟漪寿命。通过对不同角度(8“8，qr)的散射光的光谱分析，我们可以确定作为波长A的函数的波纹频率和寿命z。然而，请注意，由于rtpplon频率和u/2v通常小于20兆赫，因此需要相当大的仪器分辨率。在较早的一篇文章中，我们描述了利用法布里-珀罗涉仪对波长A=1.2x/n的表面振动引起的散射光的光谱分析。紧身上衣。然而，无法解决，只有发现了一个全面的线条加宽。我们现在报道用光学外差光谱学方法解析散射光谱的结果。这些结果明确地证明了来自热波纹的散射，并允许确定波纹色散关系。给出了波长A在大约(1.84到3.68)×10‘厘米之间的甲醇的具体数据。实验安排如下。
space light wavelength, and 8, is the polar angle of the light beam incidentfrom belowthe surface. The surface vibrations are damped by viscosity, and the shape of the lines of the doublet is Lorentzian, with a half-intensity width A~= 2/T, where T can be considered the ripplon lifetime. By spectral analysis of the scattered light at different values of the angles (8 „8, qr), we can determine the ripplonfrequency~ and lifetime z as functions of the wave-length A. Note, however, that considerable instrumental resolution is required, since the rtpplon frequency &u/2v is usually less than 20 MHz.In an earlier paper'we described a spectral analysis of the scattered light from surface vibrations of wavelength A= 1. 2X/n by means of a Fabry-Perot interferometer. The doublet. could not be resolved, however, and only an over-all line broadening was found. We now report results in which the scattered light spec-trum has been resolved by means of optical heterodyne spectroscopy.~' These results un-ambiguously demonstrate scattering from ther-mal ripplons and permit the determinationof the ripplon dispersion relation. Specific data are presented for methanol at wavelengths A between approximately(1. 84 and 3. 68) X10'cm. The experimental arrangement is as follows.'