Single-cavity bi-color laser enabled by optical anti-parity-time symmetry

The exploration of quantum inspired symmetries in optical systems has spawned promising physics and provided fertile ground for developing devices exhibiting exotic functionalities. Founded on the anti-parity–time (APT) symmetry that is enabled by both spatial temporal interplay between gain loss, we demonstrate theoretically numerically bi-color lasing a single micro-ring resonator with spatiotemporal modulation along its azimuthal direction. In contrast to conventional multi-mode lasers have mixed-frequency output, our laser exhibits stable, demultiplexed, tunable emission at different output ports. Our APT-symmetry-based may point out new route realizing compact on-chip coherent multi-color light sources.