Nonreciprocal conversion between microwave and optical photons in electro-optomechanical systems

TLDR

We propose to demonstrate nonreciprocal conversion between microwave and optical photons in an electro‑optomechanical system that couples the two modes indirectly via two non‑degenerate mechanical modes. The conversion is achieved by breaking time‑reversal symmetry, enabling constructive interference for one direction and destructive interference for the opposite, and can be extended to a three‑port circulator by adding an auxiliary optical mode coupled to a mechanical mode. The nonreciprocal response appears at two distinct frequencies with opposite directions, and the proposal enables nonreciprocal conversion between any two modes of different frequencies.

Abstract

We propose to demonstrate nonreciprocal conversion between microwave and optical photons in an electro-optomechanical system where a microwave mode and an optical mode are coupled indirectly via two non-degenerate mechanical modes. The nonreciprocal conversion is obtained in the broken time-reversal symmetry regime, where the conversion of photons from one frequency to the other is enhanced for constructive quantum interference while the conversion in the reversal direction is suppressed due to destructive quantum interference. It is interesting that the nonreciprocal response between the microwave and optical modes in the electro-optomechanical system appears at two different frequencies with opposite directions. The proposal can be used to realize nonreciprocal conversion between photons of any two distinctive modes with different frequencies. Moreover, the electro-optomechanical system can also be used to construct a three-port circulator for three optical modes with distinctively different frequencies by adding an auxiliary optical mode coupled to one of the mechanical modes.