金纳米粒子的非线性共振散射及光强度函数研究

液相金纳米粒子在320nm、470nm、580nm720nm处产生四个共振散射峰。它是一种非线性光学介质，当入射光的频率v不同时可获得金纳米粒子的2v倍频、v/2分频、v/3分频、2v/3 分频、3v／2分频散射峰。探讨了影响液相金纳米粒子散射光信号强度I（λ）的主要因素即散射光能量分布、粒径d、△λ（λem-λex)和散射光辐射度Rλex。给出了共振散射光强度与△λ之间的高斯分布函数。建立了一个合理的金纳米粒子的共振散射光强度函数。

A Study of the Nonlinear Scattering for Au Nanoparticles in Liquid and its Light Intensity Function

The Au nanoparticles in liquid were prepared by means of microwave procedure. The diameter was determined by transmission electron microscope. There are four resonance scattering peaks at 320nm, 470nm, 580nm and 720nm respectively. It is a nonlinear scattering medium. A 1/2 fraction frequency scattering peak at 580nm(1/2×1.03×1015Hz) and a 1/3 fraction frequency scattering peak at 870nm(1/3×1.03×1015Hz) were obtained as the excitation wavelength is at 290nm (1.03×1015Hz). When the excitation wavelength is at 580nm(5.02×1014Hz), It exhibits a double frequency scattering peak at 290nm(2×5.02×1014Hz) and a 2/3 fraction frequency scattering peak at 870nm(2/3×5.02×1014Hz).When the excitation wavelength is at 870nm(3.34×1014Hz), a three-times frequency scattering peak at 290nm(3×3.34×1014Hz) and a 3/2 fraction frequency scattering peak at 580nm(3/2×3.34×1014Hz) were observed. The influence of the scattering light intensity distribution, diameter, △λ(λex-λem) and the spectral radiance of scattering Rλ. emitted by the cluster on scattering signal I(λ) has been considered. The Gauss function between the intensity and △λ were obtained. A reasonable scattering light intensity function for An nanoparticles in liquid has been proposed.