All-Dielectric Resonant Cavity Electro-Optic Transduction Between Microwave and Telecom

TL;DR

This paper introduces an all-dielectric resonant transducer using lithium niobate for efficient microwave-to-telecom photon conversion, achieving high efficiency and low noise at room temperature, advancing quantum transduction technology.

Contribution

The work demonstrates a novel all-dielectric electro-optic transducer with triply resonant operation, enabling efficient microwave-optical photon conversion without metal electrodes.

Findings

Achieved percent-level photon conversion efficiency

Demonstrated triply resonant operation with high quality factors

Established potential for quantum microwave-optical transduction

Abstract

We present a resonant electro-optic transducer for efficient conversion between microwave and telecom wavelength photons. Our platform employs a bulk lithium niobate crystal whose large dielectric constant creates wavelength-scale confinement of microwave photons. By incorporating this crystal within a high-finesse Fabry - Perot optical cavity, microwave photons couple to optical photons through the electro-optic effect. We demonstrate the ability to tune our system into triply resonant operation, where microwave photons, optical pump photons, and upconverted optical photons are simultaneously resonant with high quality factor electromagnetic modes of the system. The device achieves photon number conversion efficiency at the percent level, comparable to state-of-the-art devices at room temperature -- sufficient to resolve the thermal occupation of the microwave mode -- while avoiding the noise and loss associated with metal electrodes. These results establish our all-dielectric devices as a promising platform for high-precision sensing of optically detected microwave fields and as a viable route toward single-photon-level microwave - optical quantum transduction.