Robb G R M, McNeil B W J
Department of Physics, John Anderson Building, University of Strathclyde, Glasgow G4 0NG, Scotland.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Feb;67(2 Pt 2):025603. doi: 10.1103/PhysRevE.67.025603. Epub 2003 Feb 26.
It is shown that under certain conditions a collection of dielectric Rayleigh particles suspended in a viscous medium and enclosed in a bidirectional ring cavity pumped by a strong laser field can produce a new modulational instability transverse to the wave-propagation direction. The source of the instability is collective Rayleigh scattering i.e., the spontaneous formation of periodic longitudinal particle-density modulations and a backscattered optical field. Using a linear stability analysis a dispersion relation is derived which determines the region of parameter space in which modulational instability of the backscattered field and the particle distribution occurs. In the linear regime the pump is modulationally stable. A numerical analysis is carried out to observe the dynamics of the interaction in the nonlinear regime. In the nonlinear regime the pump field also becomes modulationally unstable and strong pump depletion occurs.
结果表明，在一定条件下，悬浮在粘性介质中并封闭在由强激光场泵浦的双向环形腔中的电介质瑞利粒子集合，能够产生一种与波传播方向垂直的新的调制不稳定性。这种不稳定性的来源是集体瑞利散射，即周期性纵向粒子密度调制和反向散射光场的自发形成。通过线性稳定性分析，推导出了一个色散关系，该关系确定了参数空间中反向散射场和粒子分布发生调制不稳定性的区域。在线性区域，泵浦是调制稳定的。进行了数值分析以观察非线性区域中相互作用的动力学。在非线性区域，泵浦场也变得调制不稳定，并且发生强烈的泵浦耗尽。
