Single-Handedness Chiral Optical Cavities

Geometrical chirality is a universal property encountered on very different length scales ranging from geometrical shapes of living organisms to drug and DNA molecules. The interaction of chiral matter with chiral light, that is, an electromagnetic field possessing a certain handedness, underlies our ability to discriminate enantiomers of chiral molecules. In this context, it is often desired to have an optical cavity that efficiently couples to only a specific (right or left) molecular enantiomer and does not couple to the opposite one. Here, we demonstrate a single-handedness chiral optical cavity supporting only an eigenmode of a given handedness and lacking modes having the opposite one. Resonant excitation of the cavity with light of appropriate handedness enables the formation of a chiral standing wave with a uniform chirality density, while the light of opposite handedness does not cause any resonant effects. Furthermore, only chiral emitters of the matching handedness efficiently interact with such a chiral eigenmode, enabling the handedness-selective strength of light-matter coupling. The proposed system expands the set of tools available for investigations of chiral matter and opens the door to studies of a chiral electromagnetic vacuum.