Periodically poled thin-film lithium niobate ring Mach Zehnder coupling interferometer for efficient quantum frequency conversion

Quantum frequency conversion is unavoidable for a true quantum communication network as most quantum memories work in the visible spectrum. Here, we propose a unique design of a quantum frequency converter based on a ring-Mach Zehnder interferometer coupled with a periodically poled thin-film lithium niobate waveguide. The proposed device can be-directionally convert quantum signals i.e. single photons from quantum memory such as SiV-center in diamond to the telecom wavelength offering conversion efficiency as high as 90% at mW pump power with noise photon rate below 0.1Hz.