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

Conference on Lasers and Electro-Optics

Generation of entangled states of large photon numbers

H. S. Eisenberg, Dirk Bouwmeester

Published Jan 1, 2004• 0 citations
Publisher

Abstract

Using intense amplified short pulses, stimulated parametric down-conversion has been studied. We generated and characterized two polarization entangled spatial modes containing up to 50 indistinguishable photon pairs.
DOI
10.1364/iqec.2004.itug5

Related papers

Generation of polarization entanglement utilizing spatially correlated photon pairs from spontaneous parametric down-conversion

T. Yamaguchi, Ryōsuke Shimizu, Yasuyoshi Mitsumori +2 more

Polarization entanglement of photons provides a superior environment to demonstrate quantum info-communication protocols. Thus far, several methods using parametric down-conversion process have been realized to generate polarization-entangled photon pairs. In this report, we propose a novel method to generate polarization entanglement from spatially correlated photon pairs and demonstrate its experimental verification.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 1, 2007•0 citations

Polarization Entanglement Converted from Spatially Correlated Photon Pairs

Ryōsuke Shimizu, T. Yamaguchi, Yasuyoshi Mitsumori +2 more

We propose and demonstrate a novel scheme for the generation of polarization entanglement from spatially correlated photon pairs generated by parametric down-conversion. Using the state, we also demonstrate the violation of Bell's inequality.

The Rochester Conferences on Coherence and Quantum Optics and the Quantum Information and Measurement meeting•Jan 1, 2007•0 citations

Engineering Spatial Entanglement of Photon Pairs Generated from Parametric Down-Conversion

So-Young Baek, Fumihiro Kaneda, Yasuyoshi Mitsumori +1 more

We present our recent progress on developing a parametric down-conversion source producing highly entangled photons in spatial mode toward quantum-enhanced spa-tial measurements. The degree of transverse spatial entanglement is engineered and characterized.

Quantum 2.0 Conference and Exhibition•Jan 1, 2023•0 citations

Theory of an Entanglement Laser

Christoph Simon, Dik Bouwmeester

We consider the creation of polarization entangled light from parametric down-conversion driven by an intense pulsed pump field inside a cavity. The multiphoton states produced are close approximations to singlet states of two very large spins. A criterion is derived to quantify the entanglement of such states. We study the dynamics of the system in the presence of losses and other imperfections, concluding that the creation of strongly entangled states with photon numbers up to a million seems achievable.

arXiv:quant-ph/0302023•Physical Review Letters•Aug 1, 2003•99 citations

Auxiliary entanglement in photon pairs for multi-photon entanglement

Warren P. Grice, Ryan S. Bennink, Philip G. Evans +2 more

A growing number of experiments make use of multiple pairs of photons generated in the process of spontaneous parametric down-conversion. We show that entanglement in unwanted degrees of freedom can adversely affect the results of these experiments. We also discuss techniques to reduce or eliminate spectral and spatial entanglement, and we present results from two-photon polarization-entangled source with almost no entanglement in these degrees of freedom. Finally, we present two methods for the generation of four-photon polarization-entangled states. In one of these methods, four-photon can be generated without the need for intermediate two-photon entanglement.

Journal of Modern Optics•Jul 25, 2012•4 citations

Coincidence free certification and quantification of spatial entanglement with stimulated parametric down conversion

M. G. Damaceno, G. H. dos Santos, N. Rubiano da Silva +2 more

Using stimulated emission, a photon pair source can be characterized by seeding the signal mode with a bright classical beam and measuring the stimulated idler field, thus replacing two-photon coincidence counting with classical intensity detection. We apply this approach to the continuous transverse spatial degrees of freedom of a down conversion source and show that it is possible to certify spatial entanglement with only intensity measurements. We demonstrate this capability through variance-based entanglement and steering witnesses, as well as the Fedorov ratio. This method is useful for studying entanglement properties of photon pair sources in conditions where alignment and photon counting measurements are difficult and time-consuming.

quant-pharXiv:2607.24718•Jul 28, 2026•0 citations
We consider the creation of polarization entangled light from parametric down-conversion driven by an intense pulsed pump field inside a cavity. The multiphoton states produced are close approximations to singlet states of two very large spins. A criterion is derived to quantify the entanglement of such states. We study the dynamics of the system in the presence of losses and other imperfections, concluding that the creation of strongly entangled states with photon numbers up to a million seems achievable.
A growing number of experiments make use of multiple pairs of photons generated in the process of spontaneous parametric down-conversion. We show that entanglement in unwanted degrees of freedom can adversely affect the results of these experiments. We also discuss techniques to reduce or eliminate spectral and spatial entanglement, and we present results from two-photon polarization-entangled source with almost no entanglement in these degrees of freedom. Finally, we present two methods for the generation of four-photon polarization-entangled states. In one of these methods, four-photon can be generated without the need for intermediate two-photon entanglement.
Using stimulated emission, a photon pair source can be characterized by seeding the signal mode with a bright classical beam and measuring the stimulated idler field, thus replacing two-photon coincidence counting with classical intensity detection. We apply this approach to the continuous transverse spatial degrees of freedom of a down conversion source and show that it is possible to certify spatial entanglement with only intensity measurements. We demonstrate this capability through variance-based entanglement and steering witnesses, as well as the Fedorov ratio. This method is useful for studying entanglement properties of photon pair sources in conditions where alignment and photon counting measurements are difficult and time-consuming.