When light interacts with matter by means of scattering and absorption, we observe the resulting color. Light also probes the symmetry of matter and the result is encoded in its polarization. In the special case of circularly-polarized light, which is especially relevant in nonlinear optics, quantum photonics, and physical chemistry, a critical dimension of symmetry is along the longitudinal direction. We examine recent advances in controlling circularly-polarized light and reveal that the commonality in these advances is in judicious control of longitudinal symmetry. In particular, in the use of high quality-factor modes in dielectric metasurfaces, the finite thickness can be used to tune the modal profile. These symmetry considerations can be applied in multiplexed optical communication schemes, deterministic control of quantum emitters, and sensitive detection of the asymmetry of small molecules.

中文翻译：

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风雨同舟：光腔如何控制自旋

当光通过散射和吸收与物质相互作用时，我们观察到由此产生的颜色。光还探测物质的对称性，结果以其偏振编码。在与非线性光学、量子光子学和物理化学特别相关的圆偏振光的特殊情况下，对称的关键维度是沿纵向。我们研究了控制圆偏振光的最新进展，并揭示了这些进展的共同点在于对纵向对称性的明智控制。特别是，在电介质超表面中使用高质量因子模式时，有限厚度可用于调整模态分布。这些对称性考虑可以应用于多路复用光通信方案、量子发射器的确定性控制、