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

Physical Review Applied

Visible-band polarization-entangled photon source by quantum frequency transduction

Renhui Chen, Sujian Niu, Zheng Ge, Zhao-Qi-Zhi Han, Xiao-Hua Wang, Hai Chang Jiang, Zhi‐Yuan Zhou, Bao-Sen Shi

Published Jul 9, 2024• 3 citations
Publisher

Abstract

Visible-band polarization-entangled photon sources (VBPEPSs) are preferred in quantum microscopy, imaging, and light-matter interactions with solid-state quantum memories, $\mathrm{N}$-$V$ centers, and trapped ions. They can be generated directly via spontaneous parametric down-conversion. However, that requires a high-power deep-ultraviolet pump laser. Additionally, the required ultraviolet-band nonlinear crystal is inefficient compared to periodically poled potassium titanyl phosphate or periodically poled lithium niobate crystals. The quantum frequency transduction of a near-infrared polarization-entangled photon source (NIPEPS) provides an effective way to overcome the drawbacks of direct generation. We demonstrate 634-nm VBPEPS generation via polarization-independent frequency transduction of 1080-nm NIPEPS. High-quality entanglement in the visible band is verified via two-photon polarization interference, Bell-inequality, and quantum-state tomography. This method could be applied to other visible wavelengths or be extended to the ultraviolet, which is difficult to generate directly. It has promising applications in quantum imaging, networks, and spectroscopy.

DOI
10.1103/physrevapplied.22.014020

Related papers

CW-pumped telecom band polarization entangled photon pair generation in a Sagnac interferometer

Yan Li, Zhi‐Yuan Zhou, Dong-Sheng Ding +1 more

Polarization entangled photon pair source is widely used in many quantum information processing applications such as teleportation, quantum communications, quantum computation and high precision quantum metrology. We report on the generation of a continuous-wave pumped 1550 nm polarization entangled photon pair source at telecom wavelength using a type-II periodically poled KTiOPO(4) (PPKTP) crystal in a Sagnac interferometer. Hong-Ou-Mandel (HOM) interference measurement yields signal and idler photon bandwidth of 2.4 nm. High quality of entanglement is verified by various kinds of measurements, for example two-photon interference fringes, Bell inequality and quantum states tomography. The source can be tuned over a broad range against temperature or pump power without loss of visibilities. This source will be used in our future experiments such as generation of orbital angular momentum entangled source at telecom wavelength for quantum frequency up-conversion, entanglement based quantum key distributions and many other quantum optics experiments at telecom wavelengths.

arXiv:1510.08191•Optics Express•Oct 26, 2015•67 citations

Pulsed Sagnac source of narrow-band polarization-entangled photons

Onur Kuzucu, Franco N. C. Wong

We demonstrate pulsed operation of a bidirectionally pumped polarization Sagnac interferometric down-conversion source and its generation of narrow-band, high-visibility polarization-entangled photons. Driven by a narrow-band, mode-locked pump at 390.35 nm, the phase-stable Sagnac source with a type-II phase-matched periodically poled ${\text{KTiOPO}}_{4}$ crystal is capable of producing 0.01 entangled pair per pulse in a 0.15-nm bandwidth centered at 780.7 nm with 1 mW of average pump power at a repetition rate of 31.1 MHz. We have achieved a mean photon-pair generation rate of as high as 0.7 pair per pulse, at which multipair events dominate and significantly reduce the two-photon quantum-interference visibility. For low generation probability $\ensuremath{\alpha}$, the reduced visibility $V=1\ensuremath{-}\ensuremath{\alpha}$ is independent of the throughput efficiency and of the polarization analysis basis, which can be utilized to yield an accurate estimate of the generation rate $\ensuremath{\alpha}$. At low $\ensuremath{\alpha}$ we have characterized the source entanglement quality in three different ways: average quantum-interference visibility of 99%, the Clauser-Horne-Shimony-Holt $S$ parameter of $2.739\ifmmode\pm\else\textpm\fi{}0.119$, and quantum state tomography with 98.85% singlet-state fidelity. The narrow-band pulsed Sagnac source of entangled photons is suitable for use in quantum information processing applications such as free-space quantum key distribution.

arXiv:0710.5390•Physical Review A•Mar 7, 2008•87 citations

A source of polarization-entangled photon pairs interfacing quantum memories with telecom photons

Clausen, C., Félix Bussières, Alexey Tiranov +5 more

We present a source of polarization-entangled photon pairs suitable for the implementation of long-distance quantum communication protocols using quantum memories. Photon pairs with wavelengths 883 nm and 1338 nm are produced by coherently pumping two periodically poled nonlinear waveguides embedded in the arms of a polarization interferometer. Subsequent spectral filtering reduces the bandwidth of the photons to 240 MHz. The bandwidth is well-matched to a quantum memory based on an Nd:YSO crystal, to which, in addition, the center frequency of the 883 nm photons is actively stabilized. A theoretical model that includes the effect of the filtering is presented and accurately fits the measured correlation functions of the generated photons. The model can also be used as a way to properly assess the properties of the source. The quality of the entanglement is revealed by a visibility of V=96.1(9)% in a Bell-type experiment and through the violation of a Bell inequality.

•Jan 1, 2014•24 citations

A source of polarization-entangled photon pairs interfacing quantum memories with telecom photons

C Clausen, F Bussières, Alexey Tiranov +5 more

We present a source of polarization-entangled photon pairs suitable for the implementation of long-distance quantum communication protocols using quantum memories. Photon pairs with wavelengths 883 nm and 1338 nm are produced by coherently pumping two periodically poled nonlinear waveguides embedded in the arms of a polarization interferometer. Subsequent spectral filtering reduces the bandwidth of the photons to 240 MHz. The bandwidth is well-matched to a quantum memory based on an Nd:YSO crystal, to which, in addition, the center frequency of the 883 nm photons is actively stabilized. A theoretical model that includes the effect of the filtering is presented and accurately fits the measured correlation functions of the generated photons. The model can also be used as a way to properly assess the properties of the source. The quality of the entanglement is revealed by a visibility of in a Bell-type experiment and through the violation of a Bell inequality.

arXiv:1405.6486•New Journal of Physics•Sep 30, 2014•55 citations

Broadband-laser-diode pumped periodically poled potassium titanyl phosphate-Sagnac polarization-entangled photon source

Neng Cai, Wu‐Hao Cai, Shun Wang +3 more

We experimentally demonstrate a polarization-entangled photon source at 810 nm using a type-II phase-matched periodically poled potassium titanyl phosphate (PPKTP) crystal pumped by a low-cost, broadband laser diode with a central wavelength of 405 nm and a typical bandwidth of 0.53 nm. The PPKTP crystal is placed in a Sagnac loop to realize the compact size and high stability. The downconverted biphotons, the signal and the idler, have typical bandwidths of 5.57 and 7.32 nm. We prepare two Bell states | Ψ + ⟩ and | Ψ − ⟩ with the fidelities of 0.948 ± 0.004 and 0.963 ± 0.002 . In the polarization correlation measurement, the visibilities are all higher than 96.2%, and in the Bell inequality test, the S value can achieve 2.78 ± 0.01 . This high-quality and low-cost entangled photon source may have many practical applications in quantum information processing.

arXiv:2105.00454•Journal of the Optical Society of America B•Nov 1, 2021•11 citations

High-efficiency single photon detection via frequency up-conversion

Aaron P. VanDevender, Paul G. Kwiat

We propose a method of single photon detection of infrared (IR) photons at potentially higher efficiencies and lower noise than allowed by traditional IR band Avalanche Photodiodes (APD). By up-converting the photon from IR, e.g., 1550 nm, to a visible wavelength in a nonlinear crystal, we can utilize the much higher efficiency of visible wavelength APDs. We have used a nonlinear crystal -- Periodically Poled Lithium Niobate (PPLN) -- and a pulsed 1064-nm Nd:YAG laser to perform the up-conversion to a 631-nm photon. When properly quasi-phase-matched, PPLN provides a large enough second order nonlinear susceptibility that near unit conversion efficiency of the IR photon into the visible should be possible. We have been able to observe peak conversion efficiencies as high as 80%, and have demonstrated scaling down to the single photon level while maintaining a background of 3 x 10-4 dark counts/count. Since the PPLN only acts on one polarization of the single photon, we also propose a 2-crystal extension of this scheme whereby orthogonal polarizations may be up-converted coherently, thereby enabling complete quantum state transduction.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Aug 5, 2003•8 citations
Visible-band polarization-entangled photon sources (VBPEPSs) are preferred in quantum microscopy, imaging, and light-matter interactions with solid-state quantum memories, N\mathrm{N}N-VVV centers, and trapped ions. They can be generated directly via spontaneous parametric down-conversion. However, that requires a high-power deep-ultraviolet pump laser. Additionally, the required ultraviolet-band nonlinear crystal is inefficient compared to periodically poled potassium titanyl phosphate or periodically poled lithium niobate crystals. The quantum frequency transduction of a near-infrared polarization-entangled photon source (NIPEPS) provides an effective way to overcome the drawbacks of direct generation. We demonstrate 634-nm VBPEPS generation via polarization-independent frequency transduction of 1080-nm NIPEPS. High-quality entanglement in the visible band is verified via two-photon polarization interference, Bell-inequality, and quantum-state tomography. This method could be applied to other visible wavelengths or be extended to the ultraviolet, which is difficult to generate directly. It has promising applications in quantum imaging, networks, and spectroscopy.
Polarization entangled photon pair source is widely used in many quantum information processing applications such as teleportation, quantum communications, quantum computation and high precision quantum metrology. We report on the generation of a continuous-wave pumped 1550 nm polarization entangled photon pair source at telecom wavelength using a type-II periodically poled KTiOPO(4) (PPKTP) crystal in a Sagnac interferometer. Hong-Ou-Mandel (HOM) interference measurement yields signal and idler photon bandwidth of 2.4 nm. High quality of entanglement is verified by various kinds of measurements, for example two-photon interference fringes, Bell inequality and quantum states tomography. The source can be tuned over a broad range against temperature or pump power without loss of visibilities. This source will be used in our future experiments such as generation of orbital angular momentum entangled source at telecom wavelength for quantum frequency up-conversion, entanglement based quantum key distributions and many other quantum optics experiments at telecom wavelengths.
We demonstrate pulsed operation of a bidirectionally pumped polarization Sagnac interferometric down-conversion source and its generation of narrow-band, high-visibility polarization-entangled photons. Driven by a narrow-band, mode-locked pump at 390.35 nm, the phase-stable Sagnac source with a type-II phase-matched periodically poled KTiOPO4{\text{KTiOPO}}_{4}KTiOPO4​ crystal is capable of producing 0.01 entangled pair per pulse in a 0.15-nm bandwidth centered at 780.7 nm with 1 mW of average pump power at a repetition rate of 31.1 MHz. We have achieved a mean photon-pair generation rate of as high as 0.7 pair per pulse, at which multipair events dominate and significantly reduce the two-photon quantum-interference visibility. For low generation probability $\ensuremath{\alpha}$, the reduced visibility $V=1\ensuremath{-}\ensuremath{\alpha}$ is independent of the throughput efficiency and of the polarization analysis basis, which can be utilized to yield an accurate estimate of the generation rate $\ensuremath{\alpha}$. At low $\ensuremath{\alpha}$ we have characterized the source entanglement quality in three different ways: average quantum-interference visibility of 99%, the Clauser-Horne-Shimony-Holt SSS parameter of $2.739\ifmmode\pm\else\textpm\fi{}0.119$, and quantum state tomography with 98.85% singlet-state fidelity. The narrow-band pulsed Sagnac source of entangled photons is suitable for use in quantum information processing applications such as free-space quantum key distribution.
We present a source of polarization-entangled photon pairs suitable for the implementation of long-distance quantum communication protocols using quantum memories. Photon pairs with wavelengths 883 nm and 1338 nm are produced by coherently pumping two periodically poled nonlinear waveguides embedded in the arms of a polarization interferometer. Subsequent spectral filtering reduces the bandwidth of the photons to 240 MHz. The bandwidth is well-matched to a quantum memory based on an Nd:YSO crystal, to which, in addition, the center frequency of the 883 nm photons is actively stabilized. A theoretical model that includes the effect of the filtering is presented and accurately fits the measured correlation functions of the generated photons. The model can also be used as a way to properly assess the properties of the source. The quality of the entanglement is revealed by a visibility of V=96.1(9)% in a Bell-type experiment and through the violation of a Bell inequality.
We present a source of polarization-entangled photon pairs suitable for the implementation of long-distance quantum communication protocols using quantum memories. Photon pairs with wavelengths 883 nm and 1338 nm are produced by coherently pumping two periodically poled nonlinear waveguides embedded in the arms of a polarization interferometer. Subsequent spectral filtering reduces the bandwidth of the photons to 240 MHz. The bandwidth is well-matched to a quantum memory based on an Nd:YSO crystal, to which, in addition, the center frequency of the 883 nm photons is actively stabilized. A theoretical model that includes the effect of the filtering is presented and accurately fits the measured correlation functions of the generated photons. The model can also be used as a way to properly assess the properties of the source. The quality of the entanglement is revealed by a visibility of in a Bell-type experiment and through the violation of a Bell inequality.
We experimentally demonstrate a polarization-entangled photon source at 810 nm using a type-II phase-matched periodically poled potassium titanyl phosphate (PPKTP) crystal pumped by a low-cost, broadband laser diode with a central wavelength of 405 nm and a typical bandwidth of 0.53 nm. The PPKTP crystal is placed in a Sagnac loop to realize the compact size and high stability. The downconverted biphotons, the signal and the idler, have typical bandwidths of 5.57 and 7.32 nm. We prepare two Bell states | Ψ + ⟩ and | Ψ − ⟩ with the fidelities of 0.948 ± 0.004 and 0.963 ± 0.002 . In the polarization correlation measurement, the visibilities are all higher than 96.2%, and in the Bell inequality test, the S value can achieve 2.78 ± 0.01 . This high-quality and low-cost entangled photon source may have many practical applications in quantum information processing.
We propose a method of single photon detection of infrared (IR) photons at potentially higher efficiencies and lower noise than allowed by traditional IR band Avalanche Photodiodes (APD). By up-converting the photon from IR, e.g., 1550 nm, to a visible wavelength in a nonlinear crystal, we can utilize the much higher efficiency of visible wavelength APDs. We have used a nonlinear crystal -- Periodically Poled Lithium Niobate (PPLN) -- and a pulsed 1064-nm Nd:YAG laser to perform the up-conversion to a 631-nm photon. When properly quasi-phase-matched, PPLN provides a large enough second order nonlinear susceptibility that near unit conversion efficiency of the IR photon into the visible should be possible. We have been able to observe peak conversion efficiencies as high as 80%, and have demonstrated scaling down to the single photon level while maintaining a background of 3 x 10-4 dark counts/count. Since the PPLN only acts on one polarization of the single photon, we also propose a 2-crystal extension of this scheme whereby orthogonal polarizations may be up-converted coherently, thereby enabling complete quantum state transduction.