Ultra-bright source of polarization-entangled photons

1998/10/02 by Paul G. Kwiat, Edo Waks, Andrew G. White +4 · 2 voices · 19 citations
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #physics.optics #quant-ph

paper · pdf · doi:10.1103/physreva.60.r773

published as Physical Review A 60, 773-776 (1999) · 4 pages, 5 encapsulated Postscript figures. To appear in Physical Review A (Rapid Communication)

arxiv published 1998/10/02 · arxiv created 1999/05/22 · arxiv updated 1999/05/22 · openalex publication_date 1999/08/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

Using the process of spontaneous parametric down conversion in a novel two-crystal geometry, one can generate a source of polarization-entangled photon pairs which is orders of magnitude brighter than previous sources. We have measured a high level of entanglement between photons emitted over a relatively large collection angle, and over a 10-nm bandwidth. As a demonstration of the source intensity, we obtained a 242-σ violation of Bell's inequalities in less than three minutes.

Citations

• Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?
• Violation of Bell's inequality under strict Einstein locality conditions
• Embedded Bell-state analysis
• Discussion of Probability Relations between Separated Systems
• New High-Intensity Source of Polarization-Entangled Photon Pairs
• Experimental Realization of Einstein-Podolsky-Rosen-BohmGedankenexperiment: A New Violation of Bell's Inequalities
• Bell's theorem. Experimental tests and implications

Cited by

• Experimental measurement of multidimensional entanglement via equivalent symmetric projection
• Proposal for optical parity state re-encoder
• Threshold distances for transmission of EPR pairs through Pauli channels
• Optimal focusing for maximal collection of entangled narrow-band photon pairs into single-mode fibers
• Generating mixtures of spatial qubits
• Experimental Teleportation of a Quantum Controlled-NOT Gate
• Absolute emission rates of spontaneous parametric down-conversion into single transverse Gaussian modes
• Scheme for generating Greenberger-Horne-Zeilinger-type states ofnphotons
• High-efficiency entangled photon pair collection in type-II parametric fluorescence
• Universal unitary gate for single-photon two-qubit states
• Proposed experiment in two-qubit linear optical photonic gates for maximal success rates
• Entanglement and purity of one- and two-photon states
• Reliable entanglement verification
• Joint spectrum mapping of polarization entanglement in spontaneous parametric down-conversion
• Spectral polarization and spectral phase control of time-energy entangled photons
• Conditional preparation of a nonclassical state in the continuous-variable regime: Theoretical study
• Hyperentanglement-assisted Bell-state analysis
• Generation of entanglement in systems of intercoupled qubits
• Quantum teleportation of multiple degrees of freedom of a single photon

Discussions

• The simple answer to your question is Yes. You can create 51/49 polarization, or 52/48 polarization, or whatever mixture you might care to produce. This can easily be seen in production of Type I enta [stackexchange, 2 points]
• Your colleague is wrong. The Hamiltonian for the type-I process with two crossed crystals is $$ \hat{H}_{\mathrm{spdc}} = \alpha_V (\hat{a}^{\dagger}_H)^2 + e^{i\varphi}\alpha_H (\hat{a}^{\dagger}_V)^ [stackexchange, 0 points]