Leskova T A, Maradudin A A, Munõz-Lopez J
Department of Physics and Astronomy, University of California, Irvine, 92697, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Mar;71(3 Pt 2B):036606. doi: 10.1103/PhysRevE.71.036606. Epub 2005 Mar 14.
We study the coherence of p-polarized light scattered from a one-dimensional weakly rough random metal surface in contact with vacuum. The mutual coherence function of the single nonzero component of the scattered magnetic field is calculated in planes parallel to, and at increasing distances from, the mean scattering surface in the vacuum region. It is found to be the sum of a contribution that is independent of the distance from the mean surface and a contribution that is a function of this distance and decays to zero over a distance of the order of the wavelength of the incident light. It is also shown that the spatial coherence of the electromagnetic field in the far field in a plane at a fixed distance from the mean surface, as a function of the relative distance along it, mimics the surface height autocorrelation function at short relative distances and oscillates with two periods, T(1) = lambda and T(2) = lambda/sin theta(0), where theta(0) is the angle of incidence. The former is due to the excitation of lateral waves, while the latter is due to the coherent interference of the multiple scattering processes that lead to the enhanced backscattering effect. In the near field the spatial coherence of the electromagnetic field measured at a fixed distance from the mean surface displays oscillations that are due to the excitation of surface plasmon polaritons. The period of these oscillations equals the wavelength of the surface plasmon polaritons, while the exponential decay of their amplitude is determined by the energy mean free path of the surface plasmon polaritons.
我们研究了从与真空接触的一维弱粗糙随机金属表面散射的p偏振光的相干性。在与真空区域中的平均散射表面平行且距离逐渐增加的平面中，计算了散射磁场单个非零分量的互相干函数。结果发现，它是一个与到平均表面的距离无关的贡献和一个与该距离有关且在入射光波长量级的距离上衰减至零的贡献之和。还表明，在距平均表面固定距离的平面中，远场中电磁场的空间相干性作为沿其相对距离的函数，在短相对距离时模仿表面高度自相关函数，并以两个周期振荡，T(1) = λ 和 T(2) = λ/sin θ(0)，其中θ(0) 是入射角。前者是由于横向波的激发，而后者是由于导致增强后向散射效应的多次散射过程的相干干涉。在近场中，在距平均表面固定距离处测量的电磁场的空间相干性显示出由于表面等离激元极化激元的激发而产生的振荡。这些振荡的周期等于表面等离激元极化激元的波长，而其振幅的指数衰减由表面等离激元极化激元的能量平均自由程决定。
