Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Optics Letters

Coherent microwave-to-optical conversion by three-wave mixing in a room temperature atomic system

K. V. Adwaith, Asha Karigowda, Charudatta Manwatkar, Fabien Bretenaker, Andal Narayanan

Published Dec 14, 2018• 32 citations
Publisher

Abstract

We experimentally observe coherent generation of a near-infrared optical field through a three-wave mixing phenomenon in an atomic energy level scheme of Rb85 atoms. This nonlinear generation process in a centro-symmetric thermally broadened atomic system is made possible through a novel interaction between induced electric and magnetic dipoles. The two-photon and three-photon coherence present in our scheme eliminates excited state decoherence. Thus, our scheme represents a minimal optical decoherence scheme which could be used to transfer quantum states between microwave-to-optical frequency regimes with near-unit fidelity.

DOI
10.1364/ol.44.000033

Related papers

Coherent Microwave-to-Optical Conversion via Six-Wave Mixing in Rydberg Atoms

Jingshan Han, Thibault Vogt, Christian Groß +3 more

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 they indicate that near-unit efficiency is possible in future experiments.

arXiv:1701.07969•Physical Review Letters•Mar 1, 2018•130 citations

Robust microwave-to-optical single-photon conversion with a Rydberg atom

Wanrang Yu, Thibault Vogt

Abstract We propose an efficient scheme for microwave-to-optical quantum frequency conversion mediated by a single atom simultaneously coupled to a superconducting microwave resonator and an optical cavity. The atom mediates efficient interactions between the two electromagnetic modes via non-linear frequency mixing owing to the presence of huge microwave transition dipole moments between nearby Rydberg states as well as suitable optical transitions between low-lying states. In the regime of four-wave mixing with off-resonant fields, the excited states can be adiabatically eliminated, leading to an effective Hamiltonian that directly describes the two-mode interaction responsible for the frequency conversion. However, in this regime, the converter is slow, hence sensitive to losses due to cavity decays. To enhance the performance of the conversion process, we employ pulse engineering to tailor the atom-field couplings. The resulting protocol exhibits high robustness against decoherence and parameter fluctuations, making it well suited for realistic experimental implementations. Our scheme provides a promising route toward high-fidelity and scalable hybrid quantum interfaces connecting superconducting and optical quantum networks.

Laser Physics Letters•Jul 1, 2026•0 citations

Simultaneous three-wave and six-wave mixing of microwave and optical fields in an atomic medium

K. N. Pradosh, J. K. Saaswath, Andal Narayanan

Rb atoms. The nonlinear processes are induced using three hyperfine levels in the D1 manifold, which cyclically interact with pump optical fields and an idler microwave field. The simultaneous appearance of TWM and SWM signals in discrete frequency channels is made possible by breaking the three-photon resonance condition. This gives rise to coherent population oscillations (CPO), which are observed experimentally. We explain through our theoretical model the role of CPO in the generation of the SWM signal and its enhancement due to parametric coupling with the input seed field in contrast to the TWM signal. Our experiment proves that a single tone microwave can be converted to multiple optical frequency channels. The simultaneous existence of TWM and SWM processes can potentially enable various types of amplification to be achieved with a single neutral atom transducer platform.

Optics Express•Apr 28, 2023•4 citations

Microwave-to-optics conversion characteristics based on four-wave mixing of Rydberg atoms at room temperature

Fang Li

Microwave-to-optics conversion is a core technology for hybrid quantum networks, enabling the integration of microwave and optical frequency domains essential for quantum communication and quantum information processing. However, the Doppler broadening effect in thermal atomic ensembles often severely limits the conversion efficiency. This study aims to propose a novel mechanism for microwave-to-optics conversion using four-wave mixing (FWM) in room-temperature Rydberg atoms, addressing the challenges posed by Doppler broadening and providing a theoretical framework for practical applications. We develop a theoretical model based on the coupled Maxwell-Bloch equations to describe the FWM process in a symmetric double-ladder four-level system. The density matrix method and perturbation method combined with Maxwell’s equations are used to derive an analytical expression for the coherence coefficient between the microwave field and the optical field. This coherence coefficient characterizes the energy transfer between the microwave and optical fields and is used to obtain an analytical expression for the FWM conversion efficiency. We use cesium vapor as a medium to analyze the propagation characteristics of the FWM efficiency and explore the effects of laser field intensity and the Doppler effect on the conversion efficiency. Our analysis reveals that the detuning effect caused by the thermal motion of atoms significantly reduces the resonance coupling efficiency. Specifically, when the Doppler frequency is lower than the natural linewidth, the conversion efficiency can be notably improved. In a Doppler-free environment, the conversion efficiency approaches unity at an optimal propagation distance. In contrast, in room-temperature cesium vapor (300 K), the conversion efficiency is significantly reduced due to Doppler broadening. However, by cooling the atoms to microkelvin temperatures, the Doppler broadening can be minimized, leading to a substantial increase in conversion efficiency. This study provides new theoretical guidance and experimental schemes for microwave-to-optics conversion at room temperature. The proposed mechanism based on Rydberg atoms provides a promising approach to overcoming the limitations imposed by Doppler broadening. Our findings are of great significance for advancing quantum information technology, especially in the context of developing efficient quantum networks.

Acta Physica Sinica•Jan 1, 2025•0 citations

Two-way conversion of microwave and terahertz radiation into optical fields in Rydberg gases

Martin Kiffner, Amir Feizpour, K. T. Kaczmarek +2 more

We show that cold Rydberg gases enable an efficient six-wave mixing process where microwave or terahertz fields are coherently converted into optical fields and vice versa. This process is made possible by the long lifetime of Rydberg states, the strong coupling of millimeter waves to Rydberg transitions and a quantum interference effect related to Electromagnetically Induced Transparency. We show that conversion efficiencies within an independent atom approach are of the order of 95% and analyse the impact of dipole-dipole interactions on our scheme. We find that effective conversion efficiencies in the presence of Rydberg-Rydberg interactions can still be as high as 85% based on an implementation with Rubidium atoms. Our frequency conversion scheme does not require cavities and can be implemented for a broad spectrum of terahertz and microwave fields due to the abundance of transitions within the Rydberg manifold.

•Jan 26, 2016•0 citations

Four-Wave Mixing Scheme in a Four-Level Ladder-Type Atomic System Based on Electromagnetically Induced Transparency

Jiahua Li, Ai-Xi Chen, Peng Ju-Cun

A nonlinear optical four-wave mixing scheme is presented and analysed for the generation of coherent light in a nearly four-level ladder-type atomic system in the context of electromagnetically induced transparency (EIT). We find that EIT can suppress nonlinear photon absorption and the peak of the generated mixing field is located at the centre of the transparency window where the loss is minimal, though there is a dip in the centre. Such a nonlinear optical process can also be used for generating coherent short-wavelength radiation.

Chinese Physics Letters•May 28, 2004•1 citation
We experimentally observe coherent generation of a near-infrared optical field through a three-wave mixing phenomenon in an atomic energy level scheme of Rb85 atoms. This nonlinear generation process in a centro-symmetric thermally broadened atomic system is made possible through a novel interaction between induced electric and magnetic dipoles. The two-photon and three-photon coherence present in our scheme eliminates excited state decoherence. Thus, our scheme represents a minimal optical decoherence scheme which could be used to transfer quantum states between microwave-to-optical frequency regimes with near-unit fidelity.
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 they indicate that near-unit efficiency is possible in future experiments.
Abstract We propose an efficient scheme for microwave-to-optical quantum frequency conversion mediated by a single atom simultaneously coupled to a superconducting microwave resonator and an optical cavity. The atom mediates efficient interactions between the two electromagnetic modes via non-linear frequency mixing owing to the presence of huge microwave transition dipole moments between nearby Rydberg states as well as suitable optical transitions between low-lying states. In the regime of four-wave mixing with off-resonant fields, the excited states can be adiabatically eliminated, leading to an effective Hamiltonian that directly describes the two-mode interaction responsible for the frequency conversion. However, in this regime, the converter is slow, hence sensitive to losses due to cavity decays. To enhance the performance of the conversion process, we employ pulse engineering to tailor the atom-field couplings. The resulting protocol exhibits high robustness against decoherence and parameter fluctuations, making it well suited for realistic experimental implementations. Our scheme provides a promising route toward high-fidelity and scalable hybrid quantum interfaces connecting superconducting and optical quantum networks.
Rb atoms. The nonlinear processes are induced using three hyperfine levels in the D1 manifold, which cyclically interact with pump optical fields and an idler microwave field. The simultaneous appearance of TWM and SWM signals in discrete frequency channels is made possible by breaking the three-photon resonance condition. This gives rise to coherent population oscillations (CPO), which are observed experimentally. We explain through our theoretical model the role of CPO in the generation of the SWM signal and its enhancement due to parametric coupling with the input seed field in contrast to the TWM signal. Our experiment proves that a single tone microwave can be converted to multiple optical frequency channels. The simultaneous existence of TWM and SWM processes can potentially enable various types of amplification to be achieved with a single neutral atom transducer platform.
Microwave-to-optics conversion is a core technology for hybrid quantum networks, enabling the integration of microwave and optical frequency domains essential for quantum communication and quantum information processing. However, the Doppler broadening effect in thermal atomic ensembles often severely limits the conversion efficiency. This study aims to propose a novel mechanism for microwave-to-optics conversion using four-wave mixing (FWM) in room-temperature Rydberg atoms, addressing the challenges posed by Doppler broadening and providing a theoretical framework for practical applications. We develop a theoretical model based on the coupled Maxwell-Bloch equations to describe the FWM process in a symmetric double-ladder four-level system. The density matrix method and perturbation method combined with Maxwell’s equations are used to derive an analytical expression for the coherence coefficient between the microwave field and the optical field. This coherence coefficient characterizes the energy transfer between the microwave and optical fields and is used to obtain an analytical expression for the FWM conversion efficiency. We use cesium vapor as a medium to analyze the propagation characteristics of the FWM efficiency and explore the effects of laser field intensity and the Doppler effect on the conversion efficiency. Our analysis reveals that the detuning effect caused by the thermal motion of atoms significantly reduces the resonance coupling efficiency. Specifically, when the Doppler frequency is lower than the natural linewidth, the conversion efficiency can be notably improved. In a Doppler-free environment, the conversion efficiency approaches unity at an optimal propagation distance. In contrast, in room-temperature cesium vapor (300 K), the conversion efficiency is significantly reduced due to Doppler broadening. However, by cooling the atoms to microkelvin temperatures, the Doppler broadening can be minimized, leading to a substantial increase in conversion efficiency. This study provides new theoretical guidance and experimental schemes for microwave-to-optics conversion at room temperature. The proposed mechanism based on Rydberg atoms provides a promising approach to overcoming the limitations imposed by Doppler broadening. Our findings are of great significance for advancing quantum information technology, especially in the context of developing efficient quantum networks.
We show that cold Rydberg gases enable an efficient six-wave mixing process where microwave or terahertz fields are coherently converted into optical fields and vice versa. This process is made possible by the long lifetime of Rydberg states, the strong coupling of millimeter waves to Rydberg transitions and a quantum interference effect related to Electromagnetically Induced Transparency. We show that conversion efficiencies within an independent atom approach are of the order of 95% and analyse the impact of dipole-dipole interactions on our scheme. We find that effective conversion efficiencies in the presence of Rydberg-Rydberg interactions can still be as high as 85% based on an implementation with Rubidium atoms. Our frequency conversion scheme does not require cavities and can be implemented for a broad spectrum of terahertz and microwave fields due to the abundance of transitions within the Rydberg manifold.
A nonlinear optical four-wave mixing scheme is presented and analysed for the generation of coherent light in a nearly four-level ladder-type atomic system in the context of electromagnetically induced transparency (EIT). We find that EIT can suppress nonlinear photon absorption and the peak of the generated mixing field is located at the centre of the transparency window where the loss is minimal, though there is a dip in the centre. Such a nonlinear optical process can also be used for generating coherent short-wavelength radiation.