All dielectric cavity electro-optic transducers for quantum transduction and sensing

Electro-optic transducers, where microwave and optical photons can directly exchange information via a nonlinear optical crystal, are a promising route for the quantum transduction, sensing, and detection of microwave signals. We are exploring resonant cavity electro-optic systems, where a high dielectric constant microwave resonator interacts with a Fabry-Perot optical cavity filled with lithium niobate. We have developed several designs for our low mode volume, high Q, all-dielectric resonators including 1D microwave photonic crystal resonators which tile lithium niobate tipped "bowtie" shaped field concentrators and mm-scale cubic "sandwich" devices employing the fundamental TE and TM modes a slab of lithium niobate sandwiched between two slabs of high dielectric constant titanium dioxide. We are developing methods to tune our structures into a triply resonant condition where optical pump photons, microwave photons, and photons at the sum of those frequencies are all resonant with electromagnetic modes our structure, in order to achieve efficient signal transduction. Because our all-dielectric devices operate well at room temperature, we are exploring applications such as temperature metrology via optically detecting microwave blackbody photons. Ultimately, our devices operated at cryogenic temperatures will achieve single photon level microwave – optical quantum transduction to coherently couple superconducting qubits to room temperature fiber optic networks.