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

arXiv:0912.3194 · Optics Letters

Quasi-phase-matched concurrent nonlinearities in periodically poled KTiOPO_4 for quantum computing over the optical frequency comb

Matthew Pysher, Alon Bahabad, Peng Peng, Ady Arie, Olivier Pfister

Published Feb 9, 2010• 22 citations
arXivHTMLPDF

Abstract

We report the successful design and experimental implementation of three coincident nonlinear interactions, namely ZZZ (type 0), ZYY (type I), and YYZ/YZY (type II) second-harmonic generation of 780 nm light from a 1560 nm pump beam in a single, multigrating, periodically poled KTiOPO(4) crystal. The resulting nonlinear medium is the key component for making a scalable quantum computer over the optical frequency comb of a single optical parametric oscillator.

DOI
10.1364/ol.35.000565

Related papers

Design of the Periodically Poled KTiOPO_4 Generating 852 and 1550 nm Bicolor Entangled Lights

Jiangrui Gao

In this paper,we theoretically design the second-order nonlinear periodically poled KTiOPO4 crystal(PPKTP) by the 0-type quasi phase matching of nonlinear coefficients d33.The period of PPKTP is 10.7 microns at 20 centigrade degree.The bicolor entanglement of 852 nm signal light and 1550 nm idle light can be generated when an optical parametric oscillator of the PPKTP is pumped by 550 nm light.One of entangled beams corresponds to Cs atomic transition line,the other corresponds to optical fiber communication wavelength.The entanglement is of importance for the quantum information network and atomic information storage.

Acta Sinica Quantum Optica•Jan 1, 2011•0 citations

Observation of triply coincident nonlinearities in periodically poled KTiOPO_4

Raphael C. Pooser, Olivier Pfister

We report the simultaneous quasi-phase-matching of all three possible nonlinearities for propagation along the X axis of periodically poled (PP) KTiOPO4 (KTP) for second-harmonic generation of 745 nm pulsed light from 1490 nm subpicosecond pulses in a PPKTP crystal with a 45.65 microm poling period. This confirms the recent Sellmeier fits for KTP by Kato and Takaoka [Appl. Opt. 41, 5040 (2002)]. Such coincident nonlinearities are of importance for realizing compact sources of multipartite continuous-variable entanglement [Pfister et al., Phys. Rev. A 70, 020302 (2004)], and we propose a new simpler method for entangling four fields on the basis of this triple coincidence.

arXiv:quant-ph/0505130•Optics Letters•Oct 1, 2005•54 citations

Observing multiple processes of backward-phase-matching spontaneous parametric downconversion in a single-periodic crystal

Mingyuan Gao, Yin‐Hai Li, Zheng Ge +4 more

A nonlinear process based on backward quasi-phase matching (BQPM) can be used to realize mirrorless optical parametric oscillation, the generation of paired photons with a separable joint spectral amplitude and narrow wavelength bandwidth, and the preparation of counterpropagating polarization-entangled photons, which shows distinct advantages over some applications based on forward quasi-phase matching. In this work, three types of BQPM in a bulk periodically poled potassium titanyl phosphate crystal with a single period are theoretically analyzed. Experimentally, the harmonic wave generated by second-harmonic generation in type 0 and type I exhibits a narrow bandwidth of 15.5 GHz. Furthermore, photon pairs generated by spontaneous parametric downconversion in all types of BQPM (type 0, type I, and type II) at 7th order are observed and characterized. Their coincidence-to-accidental ratios are all greater than 5 × 10 3 in the pump power range from 10 mW to 500 mW. This research lays the foundation for further applications of BQPM in nonlinear optics, quantum optics, and quantum information processing.

Optics Letters•Jul 5, 2023•6 citations

Extended phase matching of second-harmonic generation in periodically poled KTiOPO4 with zero group-velocity mismatch

Friedrich König, Franco N. C. Wong

Under extended phase-matching conditions, the first frequency derivative of the wave-vector mismatch is zero and the phase-matching bandwidth is greatly increased. We present extensive three-wave mixing measurements of the wave-vector mismatch and obtain improved Sellmeier equations for KTiOPO4. We observed a type-II extended phase-matching bandwidth of 100 nm for second-harmonic generation in periodically poled KTiOPO4, centered at the fundamental wavelength of 1584 nm. Applications in quantum entanglement and frequency metrology are discussed.

Applied Physics Letters•Feb 27, 2004•104 citations

Mode-locked biphoton generation by concurrent quasi-phase-matching

Y. F. Bai, Ping Xu, Zhenda Xie +2 more

We report a scheme for mode-locked biphoton generation by engineering quasi-phase-matching materials. An aperiodically poled lithium tantalate is designed to supply multiple reciprocal vectors for two-photon frequency comb generation. Temporally, such two-photon state exhibits mode-locked pulse train. The two-photon pulse duration reaches 4.2 fs when the frequency comb is centered at 800 nm and covers 442 nm. The HOM interference of the mode-locked biphoton approaches a 1.26-$\ensuremath{\mu}$m dip and exhibits a reappearance of dip and peak, which can be taken as a new scheme for engineering quantum light source. Furthermore, we also design another aperiodically poled crystal to generate two sets of frequency combs. The HOM interference will appear as a revival of spatial beatings. The mode-locked biphotons suggest applications in precise time synchronization, quantum metrology, quantum optical coherence tomography, and quantum computing.

Physical Review A•May 7, 2012•7 citations

Generation of two types of nonclassical optical states using an optical parametric oscillator with a PPKTP crystal

Meiru Huo, Jiliang Qin, Zhihui Yan +2 more

As important members of nonclassical states of light, squeezed states and entangled states are basic resources for realizing quantum measurements and constructing quantum information networks. We experimentally demonstrate that the two types of nonclassical optical states can be generated from an optical parametric oscillator (OPO) involving a periodically poled KTiOPO4 crystal with a domain-inversion period of 51.7 μm, by changing the polarization of the pump laser. When a vertically polarized 671 nm laser is used to pump the OPO, the intra-cavity frequency-down-conversion with type-0 quasi-phase matching is realized and the output optical beam is a quadrature amplitude squeezed state of light at the wavelength of 1342 nm with the fluctuation of quadrature component of 3.17 dB below the quantum noise limit (QNL). If the pump laser is horizontally polarized, the condition of the type-II quasi-phase matching is satisfied and the output optical beam becomes Einstein-Podolsky-Rosen entangled state of light with correlation variances of both quadrature amplitude-sum and quadrature phase-difference of 2.2 dB below the corresponding QNL.

Applied Physics Letters•Nov 28, 2016•16 citations
We report the successful design and experimental implementation of three coincident nonlinear interactions, namely ZZZ (type 0), ZYY (type I), and YYZ/YZY (type II) second-harmonic generation of 780 nm light from a 1560 nm pump beam in a single, multigrating, periodically poled KTiOPO(4) crystal. The resulting nonlinear medium is the key component for making a scalable quantum computer over the optical frequency comb of a single optical parametric oscillator.
In this paper,we theoretically design the second-order nonlinear periodically poled KTiOPO4 crystal(PPKTP) by the 0-type quasi phase matching of nonlinear coefficients d33.The period of PPKTP is 10.7 microns at 20 centigrade degree.The bicolor entanglement of 852 nm signal light and 1550 nm idle light can be generated when an optical parametric oscillator of the PPKTP is pumped by 550 nm light.One of entangled beams corresponds to Cs atomic transition line,the other corresponds to optical fiber communication wavelength.The entanglement is of importance for the quantum information network and atomic information storage.
We report the simultaneous quasi-phase-matching of all three possible nonlinearities for propagation along the X axis of periodically poled (PP) KTiOPO4 (KTP) for second-harmonic generation of 745 nm pulsed light from 1490 nm subpicosecond pulses in a PPKTP crystal with a 45.65 microm poling period. This confirms the recent Sellmeier fits for KTP by Kato and Takaoka [Appl. Opt. 41, 5040 (2002)]. Such coincident nonlinearities are of importance for realizing compact sources of multipartite continuous-variable entanglement [Pfister et al., Phys. Rev. A 70, 020302 (2004)], and we propose a new simpler method for entangling four fields on the basis of this triple coincidence.
A nonlinear process based on backward quasi-phase matching (BQPM) can be used to realize mirrorless optical parametric oscillation, the generation of paired photons with a separable joint spectral amplitude and narrow wavelength bandwidth, and the preparation of counterpropagating polarization-entangled photons, which shows distinct advantages over some applications based on forward quasi-phase matching. In this work, three types of BQPM in a bulk periodically poled potassium titanyl phosphate crystal with a single period are theoretically analyzed. Experimentally, the harmonic wave generated by second-harmonic generation in type 0 and type I exhibits a narrow bandwidth of 15.5 GHz. Furthermore, photon pairs generated by spontaneous parametric downconversion in all types of BQPM (type 0, type I, and type II) at 7th order are observed and characterized. Their coincidence-to-accidental ratios are all greater than 5 × 10 3 in the pump power range from 10 mW to 500 mW. This research lays the foundation for further applications of BQPM in nonlinear optics, quantum optics, and quantum information processing.
Under extended phase-matching conditions, the first frequency derivative of the wave-vector mismatch is zero and the phase-matching bandwidth is greatly increased. We present extensive three-wave mixing measurements of the wave-vector mismatch and obtain improved Sellmeier equations for KTiOPO4. We observed a type-II extended phase-matching bandwidth of 100 nm for second-harmonic generation in periodically poled KTiOPO4, centered at the fundamental wavelength of 1584 nm. Applications in quantum entanglement and frequency metrology are discussed.
We report a scheme for mode-locked biphoton generation by engineering quasi-phase-matching materials. An aperiodically poled lithium tantalate is designed to supply multiple reciprocal vectors for two-photon frequency comb generation. Temporally, such two-photon state exhibits mode-locked pulse train. The two-photon pulse duration reaches 4.2 fs when the frequency comb is centered at 800 nm and covers 442 nm. The HOM interference of the mode-locked biphoton approaches a 1.26-$\ensuremath{\mu}$m dip and exhibits a reappearance of dip and peak, which can be taken as a new scheme for engineering quantum light source. Furthermore, we also design another aperiodically poled crystal to generate two sets of frequency combs. The HOM interference will appear as a revival of spatial beatings. The mode-locked biphotons suggest applications in precise time synchronization, quantum metrology, quantum optical coherence tomography, and quantum computing.
As important members of nonclassical states of light, squeezed states and entangled states are basic resources for realizing quantum measurements and constructing quantum information networks. We experimentally demonstrate that the two types of nonclassical optical states can be generated from an optical parametric oscillator (OPO) involving a periodically poled KTiOPO4 crystal with a domain-inversion period of 51.7 μm, by changing the polarization of the pump laser. When a vertically polarized 671 nm laser is used to pump the OPO, the intra-cavity frequency-down-conversion with type-0 quasi-phase matching is realized and the output optical beam is a quadrature amplitude squeezed state of light at the wavelength of 1342 nm with the fluctuation of quadrature component of 3.17 dB below the quantum noise limit (QNL). If the pump laser is horizontally polarized, the condition of the type-II quasi-phase matching is satisfied and the output optical beam becomes Einstein-Podolsky-Rosen entangled state of light with correlation variances of both quadrature amplitude-sum and quadrature phase-difference of 2.2 dB below the corresponding QNL.