Optical and spin characterization of erbium-doped yttrium orthovanadate crystal for microwave to optical conversion*

Microwave to optical conversion would enable long-distance connectivity of leading quantum hardware such as superconducting qubits. Rare-earth ion is one of the candidate platforms for such conversion because of its coherent properties in both optical and microwave domains. Erbium is of particular interest due to its telecom wavelength transitions that are compatible with current telecommunication networks. Using high-resolution spectroscopy and electron paramagnetic resonance methods, we report the optical and spin properties of the erbium-doped yttrium orthovanadate crystal. The narrow inhomogeneities and strong transition dipole moments make the material promising for microwave to optical transduction. We also present an initial demonstration of microwave to optical transduction using this material.