# Coherent microwave-to-optical conversion via six-wave mixing in Rydberg atoms

## TL;DR

This paper demonstrates a coherent microwave-to-optical conversion using six-wave mixing in Rydberg atoms, achieving 0.3% efficiency and a broad bandwidth, with potential for near-unit efficiency in future work.

## Contribution

The study experimentally realizes microwave-to-optical conversion via six-wave mixing in Rydberg atoms, showing coherence transfer and high potential efficiency.

## Key findings

- Photon conversion efficiency of ~0.3% at low microwave intensities
- Conversion bandwidth exceeds 4 MHz
- Theoretical models predict near-unit efficiency achievable in future experiments

## Abstract

We present an experimental demonstration of converting a microwave field to an optical field via frequency mixing in a cloud of cold $^{87}$Rb atoms, where the microwave field strongly couples to an electric dipole transition between Rydberg states. We show that the conversion allows the phase information of the microwave field to be coherently transferred to the optical field. With the current energy level scheme and experimental geometry, we achieve a photon conversion efficiency of ~0.3% at low microwave intensities and a broad conversion bandwidth of more than 4 MHz. Theoretical simulations agree well with the experimental data, and indicate that near-unit efficiency is possible in future experiments.