When a particle is charged, electrons can move freely along its surface and influence its optical properties in the same way as a thin, nonuniform metallic layer. These electrons contribute to scattering phenomena, including resonances. We model the light scattering from charged particles and demonstrate that these resonances result from excitation of an anti-symmetric surface plasmon at the layer interfaces. The modeling explains suppression of absorption when the size of the charged particle decreases, as well as differences in the light-scattering efficiencies of as much as a factor of 2 that occur before and after the resonance. These light-scattering properties must be taken into consideration when performing remote-sensing studies of charged particles, like those in the interstellar medium and dust storms.

当粒子带电时，电子可以沿其表面自由移动并影响其光学特性，就像薄的、不均匀的金属层一样。这些电子有助于散射现象，包括共振。我们对带电粒子的光散射进行建模，并证明这些共振是由层界面处的反对称表面等离子体激发引起的。该模型解释了当带电粒子的尺寸减小时吸收的抑制，以及共振前后发生的光散射效率差异高达 2 倍。在对带电粒子（如星际介质和沙尘暴中的粒子）进行遥感研究时，必须考虑到这些光散射特性。