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Optics InfoBase Conference Papers

Generation of Polarization-Entangled Photon Pairs Using Two-Period Quasi-Phase Matched Linbo3

Wakana Ueno, Fumihiro Kaneda, Hirofumi Suzuki, Shigehiro Nagano, Atsushi Syouji, Ryōsuke Shimizu, Koji Suizu, Keiichi Edamatsu

Published Jan 1, 2011• 0 citations
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Abstract

We demonstrate the generation of polarization-entangled photon pairs at telecommunication wavelengths with type-II quasi-phase matched spontaneous parametric down-conversion (QPM-SPDC) having two poling periods. The generated two-photon polarization state was analyzed by the quantum state tomography.

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Entangled photon generation in two-period quasi-phase-matched parametric down-conversion

Wakana Ueno, Fumihiro Kaneda, Hirofumi Suzuki +5 more

We proposed and demonstrated a simple but deterministic scheme for generating polarization-entangled photon pairs at telecommunication wavelengths with type-II quasi-phase-matched spontaneous parametric down-conversion (QPM-SPDC) having two poling periods. We fabricated a LiNbO3 crystal having two poling periods so as to generate entangled photons at two wavelengths, i.e., 1506 nm and 1594 nm. We characterized the two-photon polarization state with state tomography and confirmed that the state was highly entangled.

Optics Express•Feb 22, 2012•32 citations

Generation of polarization-entangled photons using type-II doubly periodically poled lithium niobate waveguides

Krishna Thyagarajan, Jasleen Lugani, Sankalpa Ghosh +5 more

In this paper, we address the issue of the generation of nondegenerate cross-polarization-entangled photon pairs using type-II periodically poled lithium niobate. We show that, by an appropriate engineering of the quasi-phase-matching grating, it is possible to simultaneously satisfy the conditions for two spontaneous parametric down-conversion processes, namely, ordinary pump photon down conversion to either extraordinary signal and ordinary idler paired photons or to ordinary signal and extraordinary idler paired photons. In contrast to single type-II phase matching, these two processes, when enabled together, can lead to the direct production of cross-polarization-entangled states for nondegenerate signal and idler wavelengths. Such a scheme should be of great interest in applications requiring polarization-entangled nondegenerate paired photons with, for instance, one of the entangled photons at an appropriate wavelength being used for local operation or for quantum storage in an atomic ensemble and the other one at the typical wavelength of 1550 nm for propagation through an optical fiber.

arXiv:0911.0031•Physical Review A•Nov 13, 2009•60 citations

Two channels of entangled twin photons generated by quasi-phase-matched spontaneous parametric down-conversion in periodically poled lithium niobate crystals

Shiming Gao, Changxi Yang

We propose the generation of two-channel time-energy entangled twin photons based on two simultaneous first-order quasi-phase-matched (QPM) spontaneous parametric down-conversion processes in a periodically poled lithium niobate (PPLN) with a monochromatic pump. The theoretical model for the generation of the entangled photons is established, and the analytical solution is obtained in a lossless crystal with an undepleted pump assumption. The generated condition of entangled photons is achieved in terms of the QPM grating period and the pump wavelength. It is shown that two channels of entangled twin photons with different wavelengths can be created by suitably choosing the PPLN grating period once the pump wavelength is fixed, which provides the potential to introduce the wavelength division multiplexed technique into quantum information systems.

Journal of the Optical Society of America B•Apr 15, 2008•4 citations

Proposal for in-fiber generation of telecom-band polarization-entangled photon pairs using a periodically poled fiber

L. G. Helt, Eric Y. Zhu, Marco Liscidini +2 more

We treat spontaneous parametric downconversion in a periodically poled fiber, quasi-phase matched to allow for the generation of photon pairs at wavelengths within the low-loss telecommunications window. For an appropriate pump polarization, the unusual properties of such a fiber's effective chi(2) result in a biphoton wave function that is symmetric upon simultaneous exchange of downconverted photon frequencies and polarizations and that is nonzero over a wide range of downconverted frequencies. This could lead to a significant technical simplification of sources of in-fiber telecom-band polarization-entangled photons.

Optics Letters•Jul 8, 2009•24 citations

Wavelength Management Method of Telecommunication-Band Polarization-Entangled Twin Photons in Periodically Poled Lithium Niobate Crystals

Shiming Gao

The wavelength management method was theoretically investigated for the polarization-entangled twin photons in telecommunication band generated by type-II quasi-phase-matched (QPM) spontaneous parametric down-conversion (SPDC) in periodically poled lithium niobate (PPLN) crystals. The wavelength of single-color twin photons from degenerate SPDC can be controlled freely through adjusting the QPM grating period or the working temperature. Especially, adjusting the temperature is more convenient since the QPM grating period is hardly changed once the PPLN structure is fabricated. For the two-color twin photons created by nondegenerate SPDC, strict wavelength exchange of the o-polarization and the e-polarization photons can be realized easily only by tuning the working temperature without pump or structure change.

ACTA PHOTONICA SINICA•Jan 1, 2007•0 citations

Counterpropagating entangled photons in a periodically poled nonlinear waveguide

Mark C. Booth, Mete Atatüre, Giovanni Di Giuseppe +3 more

Entangled photons, which may be generated through the process of spontaneous parametric down-conversion (SPDC) in a crystal with /spl chi//sup (2)/ nonlinearity, have long been in the spotlight for quantum-optics experiments. The generation of entangled photons by quasi-phase matching (QPM) in lithium niobate offers the promise of increased photon-pair production and, with the integration of a waveguide structure, control of the spatial characteristics of the down-converted photons. It turns out that the use of a waveguide structure, in conjunction with periodic poling to achieve quasi-phase matching, offers another critically important feature: the possibility of generating counterpropagating signal and idler photons. We consider the conditions required for generating counterpropagating photon beams and explore some of the unique properties of this source of light using a periodically poled LiNbO/sub 3/ waveguide.

IEEE Lasers and Electro-Optics Society Annual Meeting (LEOS)•Jun 26, 2003•2 citations
We proposed and demonstrated a simple but deterministic scheme for generating polarization-entangled photon pairs at telecommunication wavelengths with type-II quasi-phase-matched spontaneous parametric down-conversion (QPM-SPDC) having two poling periods. We fabricated a LiNbO3 crystal having two poling periods so as to generate entangled photons at two wavelengths, i.e., 1506 nm and 1594 nm. We characterized the two-photon polarization state with state tomography and confirmed that the state was highly entangled.
In this paper, we address the issue of the generation of nondegenerate cross-polarization-entangled photon pairs using type-II periodically poled lithium niobate. We show that, by an appropriate engineering of the quasi-phase-matching grating, it is possible to simultaneously satisfy the conditions for two spontaneous parametric down-conversion processes, namely, ordinary pump photon down conversion to either extraordinary signal and ordinary idler paired photons or to ordinary signal and extraordinary idler paired photons. In contrast to single type-II phase matching, these two processes, when enabled together, can lead to the direct production of cross-polarization-entangled states for nondegenerate signal and idler wavelengths. Such a scheme should be of great interest in applications requiring polarization-entangled nondegenerate paired photons with, for instance, one of the entangled photons at an appropriate wavelength being used for local operation or for quantum storage in an atomic ensemble and the other one at the typical wavelength of 1550 nm for propagation through an optical fiber.
We propose the generation of two-channel time-energy entangled twin photons based on two simultaneous first-order quasi-phase-matched (QPM) spontaneous parametric down-conversion processes in a periodically poled lithium niobate (PPLN) with a monochromatic pump. The theoretical model for the generation of the entangled photons is established, and the analytical solution is obtained in a lossless crystal with an undepleted pump assumption. The generated condition of entangled photons is achieved in terms of the QPM grating period and the pump wavelength. It is shown that two channels of entangled twin photons with different wavelengths can be created by suitably choosing the PPLN grating period once the pump wavelength is fixed, which provides the potential to introduce the wavelength division multiplexed technique into quantum information systems.
We treat spontaneous parametric downconversion in a periodically poled fiber, quasi-phase matched to allow for the generation of photon pairs at wavelengths within the low-loss telecommunications window. For an appropriate pump polarization, the unusual properties of such a fiber's effective chi(2) result in a biphoton wave function that is symmetric upon simultaneous exchange of downconverted photon frequencies and polarizations and that is nonzero over a wide range of downconverted frequencies. This could lead to a significant technical simplification of sources of in-fiber telecom-band polarization-entangled photons.
The wavelength management method was theoretically investigated for the polarization-entangled twin photons in telecommunication band generated by type-II quasi-phase-matched (QPM) spontaneous parametric down-conversion (SPDC) in periodically poled lithium niobate (PPLN) crystals. The wavelength of single-color twin photons from degenerate SPDC can be controlled freely through adjusting the QPM grating period or the working temperature. Especially, adjusting the temperature is more convenient since the QPM grating period is hardly changed once the PPLN structure is fabricated. For the two-color twin photons created by nondegenerate SPDC, strict wavelength exchange of the o-polarization and the e-polarization photons can be realized easily only by tuning the working temperature without pump or structure change.
Entangled photons, which may be generated through the process of spontaneous parametric down-conversion (SPDC) in a crystal with /spl chi//sup (2)/ nonlinearity, have long been in the spotlight for quantum-optics experiments. The generation of entangled photons by quasi-phase matching (QPM) in lithium niobate offers the promise of increased photon-pair production and, with the integration of a waveguide structure, control of the spatial characteristics of the down-converted photons. It turns out that the use of a waveguide structure, in conjunction with periodic poling to achieve quasi-phase matching, offers another critically important feature: the possibility of generating counterpropagating signal and idler photons. We consider the conditions required for generating counterpropagating photon beams and explore some of the unique properties of this source of light using a periodically poled LiNbO/sub 3/ waveguide.