论文标题
关于MIE光学腔的螺旋性保护
On the helicity conservation for Mie optical cavities
论文作者
论文摘要
在光 - 物质相互作用的背景下进行的螺旋性研究是研究的越来越多。但是，散射器内部光场的螺旋含量的某些基本方面被忽略了。在这项工作中，我们证明了无损球形腔内的光场的螺旋性不能是由于散射事件而被保守的，也不能被弹出。根本的原因是内部电气和磁性MIE系数不能同时振幅相等且相等/相对相位。无论折射率，球体的大小和多极顺序如何，我们的分析演示都可以实现。此外，我们表明可以保留有损球内的光场的螺旋性。这一事实与散射场的行为形成鲜明对比，当球体有损失时，其螺旋含量不能准确地保存。最后，我们表明内部场的螺旋含量可以通过增益进行翻转以获取材料。
The study of helicity in the context of light-matter interactions is an increasing area of research. However, some fundamental aspects of the helicity content of light fields inside scatterers have been overlooked. In this work, we demonstrate that the helicity of light fields inside lossless spherical cavities cannot be either conserved or sign-flipped as a result of a scattering event. The underlying reason is that the internal electric and magnetic Mie coefficients cannot simultaneously oscillate with equal amplitude and equal/opposite phase. Our analytical demonstration is fulfilled regardless of the refractive index, sphere size, and multipolar order. In addition, we show that the helicity of light fields inside lossy spheres can be conserved. This fact is in striking contrast to the behavior of the scattered field, whose helicity content cannot be conserved precisely when the sphere has losses. Finally, we show that the helicity content of internal fields can be flipped for materials with gain.
