Nonreciprocal light propagation on an integrated silicon photonic chip

We have designed, fabricated, and tested a CMOS compatible silicon waveguide system that demonstrates nonreciprocal light propagation on-chip, by mimicking microscopic non-Hermitian optical potentials for guided light and thus spontaneously breaking parity-time symmetry. Experiments were performed at 1.55 μm wavelength for potential telecommunication applications.