Optical wavelength conversion of quantum states with optomechanics

An optomechanical interface that converts quantum states between optical fields with distinct wavelengths is proposed. A mechanical mode couples to two optical modes via radiation pressure and mediates the quantum state mapping between the two optical modes. A sequence of optomechanical $\ensuremath{\pi}/2$ pulses enables state-swapping between optical and mechanical states, as well as the cooling of the mechanical mode. Theoretical analysis shows that high-fidelity conversion can be realized for states with small photon numbers in systems with experimentally achievable parameters. The pulsed conversion process also makes it possible to maintain high conversion fidelity at elevated bath temperatures.