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

Two-photon states generated from a continuous wave source

Anne E. B. Nielsen, Klaus Mølmer

Published Dec 15, 2006• 0 citations
OpenAlex

Abstract

Conditional preparation of two-photon states from a continuous wave non-degenerate optical parametric oscillator is investigated. We derive the phase space Wigner function for the output state conditioned on two nearby photo detection events, and we maximize its overlap with a two-photon state by varying the temporal output state mode function. In the low intensity limit, we generalize to n-photon state production. We find a simple expression for the conditional output, and from this we determine the optimal output state mode function and n-photon state fidelity.

Related papers

Photon number states generated from a continuous-wave light source

Anne E. B. Nielsen, Klaus Mølmer

Conditional preparation of photon number states from a continuous-wave nondegenerate optical parametric oscillator is investigated. We derive the phase space Wigner function for the output state conditioned on photodetection events that are not necessarily simultaneous, and we maximize its overlap with the desired photon number state by choosing the optimal temporal output state mode function. We present a detailed numerical analysis for the case of two-photon state generation from a parametric oscillator driven with an arbitrary intensity below threshold, and in the low-intensity limit we present a formalism that yields the optimal output state mode function and fidelity for higher-photon-number states.

arXiv:quant-ph/0612129•Physical Review A•Apr 2, 2007•16 citations

Single-photon-state generation from a continuous-wave nondegenerate optical parametric oscillator

Anne E. B. Nielsen, Klaus Mølmer

We present a theoretical treatment of conditional preparation of one-photon states from a continuous-wave nondegenerate optical parametric oscillator. We obtain an analytical expression for the output state Wigner function, and we maximize the one-photon state fidelity by varying the temporal mode function of the output state. We show that a higher production rate of high fidelity Fock states is obtained if we condition the outcome on dark intervals around trigger photo detection events.

arXiv:quant-ph/0611268•Physical Review A•Feb 6, 2007•30 citations

Photon states and Wigner functions in parametric generation

N. H. Adamyan, Gagik Yu. Kryuchkyan

The problem of preparation of photon states from two correlated modes of subharmonics generated in pulsed regime of optical parametric oscillator is investigated. Because of quantum correlation, detecting of n -photon Fock states in one mode transfers the other mode into also an n -photon state. Conditional Wigner functions are calculated whose negative parts describe the prepared photon states in cases of one-, two-, and three-photon schemes of measurements.

Journal of Contemporary Physics (Armenian Academy of Sciences)•May 6, 2008•1 citation

Experimental quantum state engineering with time-separated heraldings from a continuous-wave light source: A temporal-mode analysis

Kun Huang, Hanna Le Jeannic, Varun Boehm Verma +7 more

Conditional preparation is a well-established technique for quantum state engineering of light. A general trend is to increase the number of heralding detection events in such a realization to reach larger photon-number states or their arbitrary superpositions. In contrast to pulsed implementations, where detections only occur within the pulse window, for continuous-wave light the temporal separation of the conditioning detections is an additional degree of freedom and a critical parameter. Based on a theoretical study by Nielsen and M\o{}lmer [A. E. B. Nielsen and K. M\o{}lmer, Phys. Rev. A 75, 043801 (2007)] and on a continuous-wave two-mode squeezed vacuum from a nondegenerate optical parametric oscillator, we experimentally investigate the generation of two-photon state with tunable delay between the heralding events. The present work illustrates the temporal multimode features in play for conditional state generation based on continuous-wave light sources and quantifies the compromise between preparation rate and fidelity in this scenario.

arXiv:1511.02122•Physical Review A•Jan 20, 2016•9 citations

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

Olivier Morin, Jianli Liu, Kun Huang +3 more

Engineering non-classical states of the electromagnetic field is a central quest for quantum optics1,2. Beyond their fundamental significance, such states are indeed the resources for implementing various protocols, ranging from enhanced metrology to quantum communication and computing. A variety of devices can be used to generate non-classical states, such as single emitters, light-matter interfaces or non-linear systems3. We focus here on the use of a continuous-wave optical parametric oscillator3,4. This system is based on a non-linear χ2 crystal inserted inside an optical cavity and it is now well-known as a very efficient source of non-classical light, such as single-mode or two-mode squeezed vacuum depending on the crystal phase matching. Squeezed vacuum is a Gaussian state as its quadrature distributions follow a Gaussian statistics. However, it has been shown that number of protocols require non-Gaussian states5. Generating directly such states is a difficult task and would require strong χ3 non-linearities. Another procedure, probabilistic but heralded, consists in using a measurement-induced non-linearity via a conditional preparation technique operated on Gaussian states. Here, we detail this generation protocol for two non-Gaussian states, the single-photon state and a superposition of coherent states, using two differently phase-matched parametric oscillators as primary resources. This technique enables achievement of a high fidelity with the targeted state and generation of the state in a well-controlled spatiotemporal mode.

Journal of Visualized Experiments•May 30, 2014•7 citations

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

Olivier Morin, Jianli Liu, Kun Huang +3 more

Engineering non-classical states of the electromagnetic field is a central quest for quantum optics(1,2). Beyond their fundamental significance, such states are indeed the resources for implementing various protocols, ranging from enhanced metrology to quantum communication and computing. A variety of devices can be used to generate non-classical states, such as single emitters, light-matter interfaces or non-linear systems(3). We focus here on the use of a continuous-wave optical parametric oscillator(3,4). This system is based on a non-linear χ(2) crystal inserted inside an optical cavity and it is now well-known as a very efficient source of non-classical light, such as single-mode or two-mode squeezed vacuum depending on the crystal phase matching. Squeezed vacuum is a Gaussian state as its quadrature distributions follow a Gaussian statistics. However, it has been shown that number of protocols require non-Gaussian states(5). Generating directly such states is a difficult task and would require strong χ(3) non-linearities. Another procedure, probabilistic but heralded, consists in using a measurement-induced non-linearity via a conditional preparation technique operated on Gaussian states. Here, we detail this generation protocol for two non-Gaussian states, the single-photon state and a superposition of coherent states, using two differently phase-matched parametric oscillators as primary resources. This technique enables achievement of a high fidelity with the targeted state and generation of the state in a well-controlled spatiotemporal mode.

arXiv:1407.0183•Journal of Visualized Experiments•May 30, 2014•17 citations
Conditional preparation of two-photon states from a continuous wave non-degenerate optical parametric oscillator is investigated. We derive the phase space Wigner function for the output state conditioned on two nearby photo detection events, and we maximize its overlap with a two-photon state by varying the temporal output state mode function. In the low intensity limit, we generalize to n-photon state production. We find a simple expression for the conditional output, and from this we determine the optimal output state mode function and n-photon state fidelity.
Conditional preparation of photon number states from a continuous-wave nondegenerate optical parametric oscillator is investigated. We derive the phase space Wigner function for the output state conditioned on photodetection events that are not necessarily simultaneous, and we maximize its overlap with the desired photon number state by choosing the optimal temporal output state mode function. We present a detailed numerical analysis for the case of two-photon state generation from a parametric oscillator driven with an arbitrary intensity below threshold, and in the low-intensity limit we present a formalism that yields the optimal output state mode function and fidelity for higher-photon-number states.
Conditional preparation is a well-established technique for quantum state engineering of light. A general trend is to increase the number of heralding detection events in such a realization to reach larger photon-number states or their arbitrary superpositions. In contrast to pulsed implementations, where detections only occur within the pulse window, for continuous-wave light the temporal separation of the conditioning detections is an additional degree of freedom and a critical parameter. Based on a theoretical study by Nielsen and M\o{}lmer [A. E. B. Nielsen and K. M\o{}lmer, Phys. Rev. A 75, 043801 (2007)] and on a continuous-wave two-mode squeezed vacuum from a nondegenerate optical parametric oscillator, we experimentally investigate the generation of two-photon state with tunable delay between the heralding events. The present work illustrates the temporal multimode features in play for conditional state generation based on continuous-wave light sources and quantifies the compromise between preparation rate and fidelity in this scenario.
Engineering non-classical states of the electromagnetic field is a central quest for quantum optics1,2. Beyond their fundamental significance, such states are indeed the resources for implementing various protocols, ranging from enhanced metrology to quantum communication and computing. A variety of devices can be used to generate non-classical states, such as single emitters, light-matter interfaces or non-linear systems3. We focus here on the use of a continuous-wave optical parametric oscillator3,4. This system is based on a non-linear χ2 crystal inserted inside an optical cavity and it is now well-known as a very efficient source of non-classical light, such as single-mode or two-mode squeezed vacuum depending on the crystal phase matching. Squeezed vacuum is a Gaussian state as its quadrature distributions follow a Gaussian statistics. However, it has been shown that number of protocols require non-Gaussian states5. Generating directly such states is a difficult task and would require strong χ3 non-linearities. Another procedure, probabilistic but heralded, consists in using a measurement-induced non-linearity via a conditional preparation technique operated on Gaussian states. Here, we detail this generation protocol for two non-Gaussian states, the single-photon state and a superposition of coherent states, using two differently phase-matched parametric oscillators as primary resources. This technique enables achievement of a high fidelity with the targeted state and generation of the state in a well-controlled spatiotemporal mode.
Engineering non-classical states of the electromagnetic field is a central quest for quantum optics(1,2). Beyond their fundamental significance, such states are indeed the resources for implementing various protocols, ranging from enhanced metrology to quantum communication and computing. A variety of devices can be used to generate non-classical states, such as single emitters, light-matter interfaces or non-linear systems(3). We focus here on the use of a continuous-wave optical parametric oscillator(3,4). This system is based on a non-linear χ(2) crystal inserted inside an optical cavity and it is now well-known as a very efficient source of non-classical light, such as single-mode or two-mode squeezed vacuum depending on the crystal phase matching. Squeezed vacuum is a Gaussian state as its quadrature distributions follow a Gaussian statistics. However, it has been shown that number of protocols require non-Gaussian states(5). Generating directly such states is a difficult task and would require strong χ(3) non-linearities. Another procedure, probabilistic but heralded, consists in using a measurement-induced non-linearity via a conditional preparation technique operated on Gaussian states. Here, we detail this generation protocol for two non-Gaussian states, the single-photon state and a superposition of coherent states, using two differently phase-matched parametric oscillators as primary resources. This technique enables achievement of a high fidelity with the targeted state and generation of the state in a well-controlled spatiotemporal mode.