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

arXiv:2002.03404 · Physical Review Research

Coherent virtual absorption of light in microring resonators

Q. Zhong, L. Simonson, Tsampikos Kottos, Ramy El‐Ganainy

Published Mar 23, 2020• 17 citations
arXivHTMLPDF

Abstract

The authors investigate the process of virtual photon absorption in integrated photonic setups made of microring resonators. They show that by tailoring the temporal waveform of the input signal, it is possible to trap most of the incident energy inside the resonator with minimal leakage. This energy is then released once the input signal is switched off. The authors have also explored the robustness of this effect against various imperfections such as waveform mismatch and optical nonlinear effects.

DOI
10.1103/physrevresearch.2.013362

Related papers

Efficient excitation and control of integrated photonic circuits with virtual critical coupling

Jakob Hinney, Seunghwi Kim, Graydon J. K. Flatt +3 more

Abstract Critical coupling in integrated photonic devices enables the efficient transfer of energy from a waveguide to a resonator, a key operation for many applications. This condition is achieved when the resonator loss rate is equal to the coupling rate to the bus waveguide. Carefully matching these quantities is challenging in practice, due to variations in the resonator properties resulting from fabrication and external conditions. Here, we demonstrate that efficient energy transfer to a non-critically coupled resonator can be achieved by tailoring the excitation signal in time. We rely on excitations oscillating at complex frequencies to load an otherwise overcoupled resonator, demonstrating that a virtual critical coupling condition is achieved if the imaginary part of the complex frequency equals the mismatch between loss and coupling rate. We probe a microring resonator with tailored pulses and observe a minimum intensity transmission $$T=0.11$$ T = 0.11 in contrast to a continuous-wave transmission $$T=0.58$$ T = 0.58 , corresponding to 8 times enhancement of intracavity intensity. Our technique opens opportunities for enhancing and controlling on-demand light-matter interactions for linear and nonlinear photonic platforms.

Nature Communications•Mar 28, 2024•37 citations

Tailoring Spontaneous Four-Wave Mixing in a Ring Resonator with a Resonant Interferometric Coupler

Alice Viola, Paula L. Pagano, Francesco Malaspina +5 more

We propose an integrated device, the resonant interferometric coupler, enabling selective control over the coupling condition of a microring resonator. This can be used to tune the resonance linewidths independently, allowing for the targeted engineering of nonlinear optical interactions. We show how this can be applied to spontaneous four-wave mixing for various purposes. In the low-gain regime, we demonstrate the generation of spectrally uncorrelated photon pairs by broadening the pump resonance relative to the signal and idler. In the high-gain regime, we show how parasitic nonlinear processes can be suppressed by inhibiting undesired resonances, leading to a more efficient generation of squeezed light.

International Conference on Transparent Optical Networks•Jul 6, 2025•0 citations

Four Wave Mixing control in a photonic molecule made by silicon microring resonators

Massimo Borghi, Alessandro Trenti, Lorenzo Pavesi

Four Wave Mixing (FWM) is the main nonlinear interaction in integrated silicon devices, which finds diffuse use in all-optical signal processing and wavelength conversion. Despite the numerous works on coupled resonator devices, which showed record conversion efficiencies and broadband operation, the possibility to coherently control the strength of the stimulated FWM interaction on a chip has received very limited attention. Here, we demonstrate both theoretically and experimentally, the manipulation of FWM in a photonic molecule based on two side coupled silicon microring resonators. The active tuning of the inter-resonator phase and of their eigenfrequencies allows setting the molecule in a sub-radiant state, where FWM is enhanced with respect to the isolated resonators. On the other hand, we can reconfigure the state of the photonic molecule to have energy equipartition among the resonators, and suppress FWM by making the two Signal waves to interfere destructively in the side coupled waveguides. This work constitutes an experimental demonstration of the control of a nonlinear parametric interaction via coherent oscillation phenomena in an integrated optical device.

Scientific Reports•Jan 23, 2019•25 citations

Engineering spectrally unentangled photon pairs from nonlinear microring resonators by pump manipulation

J. B. Christensen, J. G. Koefoed, Karsten K. Rottwitt +1 more

The future of integrated quantum photonics relies heavily on the ability to engineer refined methods for preparing the quantum states needed to implement various quantum protocols. An important example of such states is quantum-correlated photon pairs, which can be efficiently generated using spontaneous nonlinear processes in integrated microring-resonator structures. In this work, we propose a method for generating spectrally unentangled photon pairs from a standard microring resonator. The method utilizes interference between a primary and a delayed secondary pump pulse to effectively increase the pump spectral width inside the cavity. This enables on-chip generation of heralded single photons with state purities in excess of 99% without spectral filtering.

arXiv:1711.02401•Optics Letters•Feb 12, 2018•46 citations

Squeezed state generation in a dual-pumped integrated microring resonator: the effects of parasitic processes

Hossein Seifoory, Z. Vernon, Dylan H. Mahler +2 more

We theoretically investigate the effects of parasitic quantum nonlinear optical processes on the generation of squeezed light in a dual-pumped integrated microring resonator coupled to a waveguide.

Conference on Lasers and Electro-Optics•Jan 1, 2021•0 citations

Backscattering in nonlinear microring resonators via a Gaussian treatment of coupled cavity modes

Will McCutcheon

Systems of coupled cavity modes have the potential to provide bright quantum optical states of light in a highly versatile manner. Microring resonators, for instance, are highly scalable candidates for photon sources. Thanks to CMOS fabrication techniques for their small footprint and the relative ease of coupling many such microrings together. However, surface roughness of the waveguides and defects in the coupler geometry routinely induce splitting of the cavity modes due to backscattering and backcoupling. The parasitic back-propagating mode in a microring leads to hybridization of the modes, altering the linear and nonlinear properties of a system of coupled cavity modes and ultimately constraining the fidelity of quantum light sources that can be produced. In this paper, we derive a comprehensive general model for Gaussian nonlinear processes in systems of coupled cavity modes based on an effective field Hamiltonian and a dispersive input–output model. The resulting dynamics of the equations of motion are evaluated in a Gaussian process formalism via symplectic transformations on the optical modes. We then use this framework to numerically model and explore the problem of backscattering in microring resonators in physically relevant parameter regimes, involving the splitting of various resonances, and we calculate the consequent impurity and heralding efficiency of various heralded photon schemes. We provide a perturbative explanation of the observations and assess the correspondence between spontaneous and stimulated processes in these systems.

arXiv:2010.09038•APL Photonics•Jun 1, 2021•11 citations
The authors investigate the process of virtual photon absorption in integrated photonic setups made of microring resonators. They show that by tailoring the temporal waveform of the input signal, it is possible to trap most of the incident energy inside the resonator with minimal leakage. This energy is then released once the input signal is switched off. The authors have also explored the robustness of this effect against various imperfections such as waveform mismatch and optical nonlinear effects.
Abstract Critical coupling in integrated photonic devices enables the efficient transfer of energy from a waveguide to a resonator, a key operation for many applications. This condition is achieved when the resonator loss rate is equal to the coupling rate to the bus waveguide. Carefully matching these quantities is challenging in practice, due to variations in the resonator properties resulting from fabrication and external conditions. Here, we demonstrate that efficient energy transfer to a non-critically coupled resonator can be achieved by tailoring the excitation signal in time. We rely on excitations oscillating at complex frequencies to load an otherwise overcoupled resonator, demonstrating that a virtual critical coupling condition is achieved if the imaginary part of the complex frequency equals the mismatch between loss and coupling rate. We probe a microring resonator with tailored pulses and observe a minimum intensity transmission T=0.11T=0.11T=0.11 T = 0.11 in contrast to a continuous-wave transmission T=0.58T=0.58T=0.58 T = 0.58 , corresponding to 8 times enhancement of intracavity intensity. Our technique opens opportunities for enhancing and controlling on-demand light-matter interactions for linear and nonlinear photonic platforms.
We propose an integrated device, the resonant interferometric coupler, enabling selective control over the coupling condition of a microring resonator. This can be used to tune the resonance linewidths independently, allowing for the targeted engineering of nonlinear optical interactions. We show how this can be applied to spontaneous four-wave mixing for various purposes. In the low-gain regime, we demonstrate the generation of spectrally uncorrelated photon pairs by broadening the pump resonance relative to the signal and idler. In the high-gain regime, we show how parasitic nonlinear processes can be suppressed by inhibiting undesired resonances, leading to a more efficient generation of squeezed light.
Four Wave Mixing (FWM) is the main nonlinear interaction in integrated silicon devices, which finds diffuse use in all-optical signal processing and wavelength conversion. Despite the numerous works on coupled resonator devices, which showed record conversion efficiencies and broadband operation, the possibility to coherently control the strength of the stimulated FWM interaction on a chip has received very limited attention. Here, we demonstrate both theoretically and experimentally, the manipulation of FWM in a photonic molecule based on two side coupled silicon microring resonators. The active tuning of the inter-resonator phase and of their eigenfrequencies allows setting the molecule in a sub-radiant state, where FWM is enhanced with respect to the isolated resonators. On the other hand, we can reconfigure the state of the photonic molecule to have energy equipartition among the resonators, and suppress FWM by making the two Signal waves to interfere destructively in the side coupled waveguides. This work constitutes an experimental demonstration of the control of a nonlinear parametric interaction via coherent oscillation phenomena in an integrated optical device.
The future of integrated quantum photonics relies heavily on the ability to engineer refined methods for preparing the quantum states needed to implement various quantum protocols. An important example of such states is quantum-correlated photon pairs, which can be efficiently generated using spontaneous nonlinear processes in integrated microring-resonator structures. In this work, we propose a method for generating spectrally unentangled photon pairs from a standard microring resonator. The method utilizes interference between a primary and a delayed secondary pump pulse to effectively increase the pump spectral width inside the cavity. This enables on-chip generation of heralded single photons with state purities in excess of 99% without spectral filtering.
Systems of coupled cavity modes have the potential to provide bright quantum optical states of light in a highly versatile manner. Microring resonators, for instance, are highly scalable candidates for photon sources. Thanks to CMOS fabrication techniques for their small footprint and the relative ease of coupling many such microrings together. However, surface roughness of the waveguides and defects in the coupler geometry routinely induce splitting of the cavity modes due to backscattering and backcoupling. The parasitic back-propagating mode in a microring leads to hybridization of the modes, altering the linear and nonlinear properties of a system of coupled cavity modes and ultimately constraining the fidelity of quantum light sources that can be produced. In this paper, we derive a comprehensive general model for Gaussian nonlinear processes in systems of coupled cavity modes based on an effective field Hamiltonian and a dispersive input–output model. The resulting dynamics of the equations of motion are evaluated in a Gaussian process formalism via symplectic transformations on the optical modes. We then use this framework to numerically model and explore the problem of backscattering in microring resonators in physically relevant parameter regimes, involving the splitting of various resonances, and we calculate the consequent impurity and heralding efficiency of various heralded photon schemes. We provide a perturbative explanation of the observations and assess the correspondence between spontaneous and stimulated processes in these systems.