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

ENTANGLED STATE PREPARATION FOR OPTICAL QUANTUM COMMUNICATION: Creating and characterizing photon pairs from Spontaneous Parametric Down Conversion inside bulk uniaxial crystals

Alexander Ling, Euk Jin Alexander Ling

Published Jan 1, 2008• 3 citations
OpenAlex

Related papers

Production of Entangled Photons via Spontaneous Parametric Down-Conversion

Logan Kaelbling

•Jan 1, 2020•0 citations

Characterizing a 474 nm Laser as a Source for Spontaneous Parametric Down Conversion

J. A. Balmer, L.C. Howard

There is an important class of experiments that characterize the properties of quantum mechanical systems using correlated photons, and a typical source for correlated photons is the process of Spontaneous Parametric Down Conversion (SPDC). SPDC is a quantum mechanical process in which a single “pump” photon is converted into two photons that have half the frequency and double the wavelength of the original photon. This process takes place inside a crystal with particular optical properties that allow for SPDC, and we used a uniaxial Beta Barium Borate crystal. A single photon counting module (SPCM) was used as a detector for the photons. Our goal was to characterize a 474 nanometer (nm) Diode Pumped Solid State (DPSS) laser as a possible source for SPDC correlated photons. Measurements of the DPSS laser radiation showed that it emitted photons with a wavelength of both 474 nm and 948 nm, which was expected. The SPDC photons produced by our apparatus would also have a wavelength of 948 nm, so we tested whether the down converted photons could be detected without the 948 nm signal from the DPSS laser overwhelming the SPCM. Software for determining the parameters of SPDC in a given system is available from the National Institute of Standards and Technology, and we used it to determine where we could expect to see SPDC photons. Initial measurements suggest that the system can produce SPDC photons, and we will continue to characterize the apparatus.

•Jan 1, 2013•0 citations

Anisotropic narrowing of biphoton wave packet distribution in spontaneous parametric down-conversion with biaxial crystal

Guangwen Huo, Tongyi Zhang, Meizhi Zhang +3 more

We investigate theoretically the strong anisotropy in the wave packet distribution of biphoton pairs generated via spontaneous parametric down-conversion (SPDC) process with biaxial crystals. From the angle relationship in biaxial crystals, we deduce the wave function of type I SPDC by considering the longitudinal detuning under paraxial approximation. Taking BiB3O6 (BIBO) as an example, we numerically simulate the single-particle and coincidence distributions in two observation planes under the optimum phase-matching scheme. In contrast to uniaxial crystals, a stronger anisotropy effect and a higher entanglement of the photon pair states are obtained, which are attributed to the complex structure of biaxial crystals. These results are important for the generation of highly entangled biphoton pairs, especially for multi-photon pairs generation.

Journal of Modern Optics•Oct 26, 2017•1 citation

Property of Entangled Photon Pairs Generated via Spontaneous Parametric Down Conversion

宋媛媛 Song Yuanyuan, 陈鼎 Chen Ding, 丛爽 Cong Shuang

Laser & Optoelectronics Progress•Jan 1, 2019•0 citations

Spontaneous Parametric Down-Conversion and Quantum Walks in Arrays of Quadratic Nonlinear Waveguides

Alexander S. Solntsev, Andrey A. Sukhorukov, Dragomir N. Neshev +1 more

We analyze the process of photon-pair generation with simultaneous quantum walks in a quadratic nonlinear waveguide array. We demonstrate that the spontaneous parametric down-conversion in the array allows for creating quantum states with strongly pronounced spatial correlations, which are qualitatively different from those possible in bulk crystals or through quantum walks in linear waveguide arrays. Most importantly, the photon correlations can be controlled entirely classically by varying the spatial profile of the pump beam or the phase-matching conditions.

arXiv:1108.6116•Physical Review Letters•Jan 10, 2012•92 citations

Multi-photon entangled states from two-crystal geometry parametric down-conversion and their application in quantum teleportation

Yongmin Li, Takayoshi Kobayashi

Optics Communications•Sep 28, 2004•3 citations
There is an important class of experiments that characterize the properties of quantum mechanical systems using correlated photons, and a typical source for correlated photons is the process of Spontaneous Parametric Down Conversion (SPDC). SPDC is a quantum mechanical process in which a single “pump” photon is converted into two photons that have half the frequency and double the wavelength of the original photon. This process takes place inside a crystal with particular optical properties that allow for SPDC, and we used a uniaxial Beta Barium Borate crystal. A single photon counting module (SPCM) was used as a detector for the photons. Our goal was to characterize a 474 nanometer (nm) Diode Pumped Solid State (DPSS) laser as a possible source for SPDC correlated photons. Measurements of the DPSS laser radiation showed that it emitted photons with a wavelength of both 474 nm and 948 nm, which was expected. The SPDC photons produced by our apparatus would also have a wavelength of 948 nm, so we tested whether the down converted photons could be detected without the 948 nm signal from the DPSS laser overwhelming the SPCM. Software for determining the parameters of SPDC in a given system is available from the National Institute of Standards and Technology, and we used it to determine where we could expect to see SPDC photons. Initial measurements suggest that the system can produce SPDC photons, and we will continue to characterize the apparatus.
We investigate theoretically the strong anisotropy in the wave packet distribution of biphoton pairs generated via spontaneous parametric down-conversion (SPDC) process with biaxial crystals. From the angle relationship in biaxial crystals, we deduce the wave function of type I SPDC by considering the longitudinal detuning under paraxial approximation. Taking BiB3O6 (BIBO) as an example, we numerically simulate the single-particle and coincidence distributions in two observation planes under the optimum phase-matching scheme. In contrast to uniaxial crystals, a stronger anisotropy effect and a higher entanglement of the photon pair states are obtained, which are attributed to the complex structure of biaxial crystals. These results are important for the generation of highly entangled biphoton pairs, especially for multi-photon pairs generation.
We analyze the process of photon-pair generation with simultaneous quantum walks in a quadratic nonlinear waveguide array. We demonstrate that the spontaneous parametric down-conversion in the array allows for creating quantum states with strongly pronounced spatial correlations, which are qualitatively different from those possible in bulk crystals or through quantum walks in linear waveguide arrays. Most importantly, the photon correlations can be controlled entirely classically by varying the spatial profile of the pump beam or the phase-matching conditions.