The Rochester Conferences on Coherence and Quantum Optics and the Quantum Information and Measurement meeting

Spatial Entanglement and Efficient Coupling to Single Spatial Modes

Warren P. Grice, Ryan S. Bennink, Douglas S. Goodman, Andrew T. Ryan

Published Jan 1, 2007• 0 citations

Abstract

Single-mode coupling efficiency of photons produced via spontaneous parametric down-conversion is limited by entanglement in the photons’ spatial degree of freedom. Results are presented illustrating the relationship between pump divergence and the photons’ spatial entanglement.

DOI: 10.1364/cqo.2007.cmi45

Related papers

Spatial entanglement and optimal single-mode coupling

Warren P. Grice, Ryan S. Bennink, D. S. Goodman +1 more

The challenge of optimizing the emission into single spatial modes of photons from spontaneous parametric down-conversion is addressed from the perspective of spatial entanglement. It is shown that single-mode coupling is most efficient in the absence of entanglement. Evidence of the relationship between spatial entanglement and pump focusing is revealed through experimental results, and numerical simulations show that spatial entanglement and single-mode coupling are optimized under nearly identical pump parameters.

Physical Review AFeb 15, 201139 citations

Spatial Entanglement and Optimal Single-Mode Coupling

Ryan S. Bennink, Warren P. Grice, D. S. Goodman +1 more

We theoretically and experimentally show that the single-mode collection efficiency of spontaneous parametric down-conversion photons is inversely related to the photons’ degree of spatial entanglement.

Frontiers in OpticsJan 1, 20090 citations

Polarization Entanglement from an Incoherent Pump

Cheng Li, Boris Braverman, Girish Ashok Kulkarni +1 more

Entangled photon states are typically produced using spontaneous parametric down-conversion (SPDC) pumped by a coherent source. For temporal and spatial degrees of freedom, the down-converted light entanglement is limited by the pump coherence. We propose an experiment to investigate whether polarization entanglement is similarly affected, aiming to produce polarization-entangled states from SPDC pumped by an LED, an incoherent pump.

Photonics North (PN)May 1, 20200 citations

Full-field mapping of spatially varying polarization entanglement generated from spontaneous parametric down-conversion

Cheng Li, Girish Kulkarni, Isaac Soward +6 more

Two-photon states generated from spontaneous parametric down-conversion (SPDC) can display entanglement in all degrees of freedom (DoFs) of light, including spatial, temporal, and polarization. The coupling between different DoFs of a two-photon state has been shown to display rich structures that enable novel and robust information processing schemes. While existing literature has studied these couplings by post-selecting the SPDC field, a comprehensive understanding of the inherent spatial-polarization coupling produced in the SPDC process is still lacking. This work produces a full spatial map of the polarization entanglement generated across the entire SPDC field, which contains an entire class of near-maximally polarization-entangled states with an average concurrence of 0.8303 +/- 0.0004. The spatial-polarization coupling manifests as radially or linearly varying polarization-entangled states, whose wavefunctions are dependent on the transverse momenta of the down-converted photons and the pump beam, respectively. Our study lays important groundwork for further exploiting the coupling between entanglement in different DoFs for future quantum technologies

arXiv:2502.03586Physical Review AppliedJun 17, 20263 citations

Four-Photon Transverse Mode Entanglement

W. Löffler, M. J. A. de Dood, Beatrix C. Hiesmayr

We show experimental evidence of quantum entanglement of 4 photons in their spatial degrees of freedom. A large fraction of the photons produced by single-pass spontaneous parametric downconversion are in the 4-particle, 3-dimensional Greenberger-Horne-Zeilinger (GHZ) state.

Frontiers in OpticsJan 1, 20130 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 ExhibitionJan 1, 20230 citations