The concept of synthetic dimensions in photonics, which was proposed past few years, has been attracting great interest and becomes one of rapidly-developing research subjects in the optical and photonic society. In an optical ring resonator under the dynamic modulation, it has been found that one could construct a synthetic dimension by utilizing the frequency degree of freedom of light and coupling different resonant modes.

We experimentally demonstrate the construction of two independent synthetic dimensions in a single optical resonator for the first time. In such two-dimensional synthetic space, we explore many important physical phenomena including the effective magnetic gauge potential for light, topological chiral one-way edge current, and also synthetic Hall ladder. Our work shows the possibility of studying a wide variety of physics associated to higher dimensions completely in simple systems by applying the concept of multiple synthetic dimensions, and therefore points to potentially manipulating and controlling light in versatile ways.

FIGURE: Observation of the chiral one-way edge current associated to the Hall ladder.

The paper has been published in Science with the title “A single photonic cavity with two independent physical synthetic dimensions”.

Link: https://science.sciencemag.org/content/367/6473/59