论文标题
通过调制拉曼光谱法确定光学捕获的粒子的尺寸
Determining size of an optically trapped particle via modulated Raman spectroscopy
论文作者
论文摘要
在调制的光学陷阱中获得的平均拉曼信号功率取决于布朗运动 - 因此，被困粒子的水动力特性。因此，除了从拉曼信号获得的分子特性外，还可以通过分析平均拉曼功率的变化来研究粒子的流体动力特性（例如大小），这是调制频率的函数。我们的结果基于过度抑制的Langevin方程，表明在给定粒径和信号采集时间的独特调制频率下，拉曼信号存在几个minimas。在典型的实验条件下，这种微型片可以低至未调制陷阱中拉曼信号的50％。
The average Raman signal power obtained in a modulated optical trap is dependent on the Brownian motion - therefore hydrodynamic properties of the trapped particle. Hence, in addition to the molecular properties obtained from the Raman signal, it is possible to study hydrodynamic properties (e.g. size) of the particle by analyzing the change in the average Raman power as a function of modulation frequency. Our results, based on the over-damped Langevin equation, show that several minimas exist for the Raman signal at unique modulating frequencies for a given particle size and signal acquisition time. In typical experimental conditions, such minimas can be as low as 50% of the Raman signal in an unmodulated trap.
