Quantum frequency conversion for QUANT-NET

Quantum frequency conversion (QFC) is widely employed in quantum networks to frequency convert photons from quantum nodes which are typically at visible wavelengths to telecommunication wavelengths. At Quantnet testbed, we connect ion traps, which emit at 854 nm, at LBNL and UCB over a fiber link of 10km via QFC to demonstrate the functionalities of quantum networks. Towards this, we simulate ridge and reverse-proton exchange-based Lithium Niobate waveguides for conversion from 854 nm to 1550 nm using a pump at 1902 nm. Furthermore we simulate all free-space components that couple 1902nm and 854nm wavelengths to the waveguide and we optimize various parameters of all these components to achieve the highest QFC efficiency possible. Further, we extend these simulations considering silicon G-centers (1280nm). This would pave the way for connecting distant heterogeneous quantum nodes.