Lee Kang Soo, Yoon Sang Youl, Lee Kyung Heon, Kim Sang Bok, Sung Hyung Jin, Kim Sang Soo
Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, South Korea.
Opt Express. 2012 Jul 30;20(16):17348-58. doi: 10.1364/OE.20.017348.
This paper describes a method for particle manipulation in a liquid-core/liquid-cladding optical waveguide system. Step-index and graded-index waveguides were modeled with consideration for, respectively, miscible and immiscible core and cladding fluids. The characteristic motions of four different particles with refractive indices of 1.59, 1.48, 1.37, and 1.22 were examined. The guided beam was assumed to be Gaussian in shape. Our results showed that high-refractive-index particles converged at the center of the core fluid due to a positive gradient force, whereas low-refractive-index particles converged at the flow periphery. The nonlinearity of the particle motion increased as the flow velocity and the guided beam waist decreased and the laser power and the particle size increased. The initial beam waist of the guided beam in the graded-index waveguide did not significantly affect the characteristics of the particle motion due to the effects of diffusion.
本文描述了一种在液芯/液包层光波导系统中进行粒子操控的方法。分别针对可混溶和不可混溶的芯层和包层流体，对阶跃折射率和渐变折射率波导进行了建模。研究了折射率分别为1.59、1.48、1.37和1.22的四种不同粒子的特征运动。假设引导光束为高斯形状。我们的结果表明，由于正梯度力，高折射率粒子在芯层流体中心汇聚，而低折射率粒子在流体周边汇聚。随着流速和引导光束束腰减小以及激光功率和粒子尺寸增大，粒子运动的非线性增加。由于扩散效应，渐变折射率波导中引导光束的初始束腰对粒子运动特性没有显著影响。
