Through thick and thin: how optical cavities control spin

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.

Automated summary

When light interacts with matter, it produces color through scattering and absorption. The symmetry of matter can be examined through the polarization of light, especially circularly-polarized light. Recent advances in controlling circularly-polarized light have shown that judicious control of longitudinal symmetry is a key factor. This can be applied in various fields such as optical communication, quantum emitters control, and detection of small molecule asymmetry.