论文标题
活性颗粒的正灭绝和负灭绝
Positive and negative extinction of active particles
论文作者
论文摘要
使用分析洛伦兹 - 我的散射形式主义和数值方法，我们分析了活动颗粒对电磁波的响应。这些颗粒由均质，非磁性和介质各向同性培养基组成。处理球形散射器和锋利和圆形的立方体。活性颗粒的吸收横截面为阴性，因此显示出其电磁反应的增益。由于散射横截面始终是正面的，因此它们的灭绝可以为正，负或零。我们构建了活性和被动介电颗粒的五级分类。我们指出了活跃散射器显示的增强的反向散射现象，还讨论了灭绝悖论和光学定理。最后，说明了使用comsol多物理和内部方法代码，说明了活动散射器非球体性对电磁反应的影响。
Using analytical Lorenz--Mie scattering formalism and numerical methods, we analyze the response of active particles to electromagnetic waves. The particles are composed of homogeneous, non-magnetic, and dielectrically isotropic medium. Spherical scatterers and sharp and rounded cubes are treated. The absorption cross-section of active particles is negative, thus showing gain in their electromagnetic response. Since the scattering cross-section is always positive, their extinction can be either positive, negative, or zero. We construct a five-class categorization of active and passive dielectric particles. We point out the enhanced backscattering phenomenon that active scatterers display, and also discuss extinction paradox and optical theorem. Finally, using COMSOL Multiphysics and an in-house Method-of-Moments code, the effects of the non-sphericity of active scatterers on their electromagnetic response are illustrated.
