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:quant-ph/0607137 · Laser Physics

Dispersion spreading of polarization-entangled states of light and two-photon interference

G. Brida, Marco Genovese, Leonid A. Krivitsky, Maria V. Chekhova

Published Apr 1, 2007• 3 citations
arXivHTMLPDF

Abstract

We study the interference structure of the second-order intensity correlation function for polarization-entangled two-photon light obtained from type II collinear frequency-degenerate spontaneous parametric down conversion (SPDC). The structure is visualized due to the spreading of the two-photon amplitude as two-photon light propagates through optical fiber with group-velocity dispersion (GVD). Because of the spreading, polarization-entangled Bell states can be obtained without any birefringence compensation at the output of the nonlinear crystal. Instead, proper time selection of the intensity correlation function is required. A birefringent material inserted at the output of the nonlinear crystal (either reducing the initial e-o delay between the oppositely polarized twin photons or increasing this delay) leads to a more complicated interference structure of the correlation function.

DOI
10.1134/s1054660x0704041x

Related papers

Interference structure of two-photon amplitude revealed by dispersion spreading

G. Brida, Marco Genovese, Leonid A. Krivitsky +1 more

We study the interference structure of the second-order intensity correlation function for polarization-entangled two-photon light obtained from type-II collinear frequency-degenerate spontaneous parametric down conversion. The structure is visualized due to the spreading of the two-photon amplitude in an optical fiber with group-velocity dispersion. A birefringent material inserted at the output of the nonlinear crystal leads to a more complicated interference structure of the correlation function.

Physical Review A•Jan 26, 2007•11 citations

Dispersion Spreading of Biphotons in Optical Fibers and Two-Photon Interference

G. Brida, Maria V. Chekhova, Marco Genovese +2 more

We present the first observation of two-photon polarization interference structure in the second-order Glauber correlation function of two-photon light generated via type-II spontaneous parametric down-conversion. In order to obtain this result, two-photon light is transmitted through an optical fiber and the coincidence distribution is analyzed by means of the start-stop method. Beyond the experimental demonstration of an interesting effect in quantum optics, these results also have considerable relevance for quantum communications.

arXiv:quant-ph/0603247•Physical Review Letters•Apr 13, 2006•34 citations

“Spreading” of a biphoton in a group-velocity-dispersion medium and two-photon interference

L. A. Krivitskiı̆, Maria V. Chekhova

It is shown that two-photon Bell states can be prepared by “spreading” of a two-photon wave packet (biphoton) in a dispersive medium without compensating for group delays between photons with orthogonal polarizations or using narrow-band filters but by selecting the time correlation function. This is possible because two-photon interference effects are manifested in the shape of the time correlation function of intensity due to its spreading.

Journal of Experimental and Theoretical Physics Letters•Feb 1, 2005•2 citations

Two-photon entanglement generation: different Bell states within the linewidth of phase-matching

G. Brida, Maria V. Chekhova, Marco Genovese +1 more

It is shown that for a phase-matched nonlinear process producing entangled states, different Bell states are generated for different mismatch values. In particular, generation of the singlet Bell state is demonstrated within the natural linewidth of collinear frequency-degenerate type-II spontaneous parametric down-conversion (SPDC) without the o-e delay compensation. The singlet state can be filtered out by spectral selection or by the time selection of the two-photon amplitude at the output of a dispersive fibre. The effect is of considerable importance for fibre quantum communication.

Optics Express•Jan 1, 2007•12 citations

New technique for the measurement of polarization-mode dispersion in optical materials and fibers

Alexander V. Sergienko, Yanhua H. Shih

Correlated pairs of photons generated in nonlinear type-II spontaneous parametric downconversion (SPDC) can be used to develop a new approach for directly measuring the group-velocity difference between two orthogonally polarized wave packets propagating inside optical materials or fibers with femtosecond time resolution. This technique can be used to improve the accuracy of polarization-mode-dispersion measurement in single-mode and high-birefringence fibers, fiber sensors, and birefringent materials, including nonlinear crystals, waveguides, Pockels cells, and Faraday rotators, in the visible and IR spectra.

Conference on Lasers and Electro-Optics•May 21, 1995•0 citations

Quantum interference using ultrafast spontaneous parametric down-conversion

Mete Atatüre, Alexander V. Sergienko, Bradley M. Jost +2 more

Summary form only given. Pairs of entangled photons display a complex quantum state that cannot be represented through a product of single-particle states. The spontaneous parametric down-conversion (SPDC) process, that takes place when a laser pulse pumps a second-order nonlinear crystal has become recently a convenient source of such nonclassical states of light in quantum optics experiments. Nonstationary effects are mainly observed when the pump pulse temporal duration is significantly shorter than the characteristic interaction time in the nonlinear crystal. We introduce a nonstationary theory of SPDC to describe the results of fourth-order quantum-interference experiments when no spectral filtering is applied to the down-converted fields. Experiments involving nonlinear SPDC crystals with three different lengths were performed. The ultraviolet laser pulses were obtained from a Ti:sapphire femtosecond laser with a second-harmonic generator. These pulses were used to pump nonlinear crystals to initiate the process of nonstationary spdc and generate orthogonally-polarized photon pairs. These pairs then went into a polarization interferometer, and the coincidence counts of the detectors at the two output ports of the interferometer were recorded.

Quantum Electronics and Laser Science Conference•Jan 20, 2003•0 citations
We study the interference structure of the second-order intensity correlation function for polarization-entangled two-photon light obtained from type II collinear frequency-degenerate spontaneous parametric down conversion (SPDC). The structure is visualized due to the spreading of the two-photon amplitude as two-photon light propagates through optical fiber with group-velocity dispersion (GVD). Because of the spreading, polarization-entangled Bell states can be obtained without any birefringence compensation at the output of the nonlinear crystal. Instead, proper time selection of the intensity correlation function is required. A birefringent material inserted at the output of the nonlinear crystal (either reducing the initial e-o delay between the oppositely polarized twin photons or increasing this delay) leads to a more complicated interference structure of the correlation function.
We study the interference structure of the second-order intensity correlation function for polarization-entangled two-photon light obtained from type-II collinear frequency-degenerate spontaneous parametric down conversion. The structure is visualized due to the spreading of the two-photon amplitude in an optical fiber with group-velocity dispersion. A birefringent material inserted at the output of the nonlinear crystal leads to a more complicated interference structure of the correlation function.
We present the first observation of two-photon polarization interference structure in the second-order Glauber correlation function of two-photon light generated via type-II spontaneous parametric down-conversion. In order to obtain this result, two-photon light is transmitted through an optical fiber and the coincidence distribution is analyzed by means of the start-stop method. Beyond the experimental demonstration of an interesting effect in quantum optics, these results also have considerable relevance for quantum communications.
It is shown that for a phase-matched nonlinear process producing entangled states, different Bell states are generated for different mismatch values. In particular, generation of the singlet Bell state is demonstrated within the natural linewidth of collinear frequency-degenerate type-II spontaneous parametric down-conversion (SPDC) without the o-e delay compensation. The singlet state can be filtered out by spectral selection or by the time selection of the two-photon amplitude at the output of a dispersive fibre. The effect is of considerable importance for fibre quantum communication.
Correlated pairs of photons generated in nonlinear type-II spontaneous parametric downconversion (SPDC) can be used to develop a new approach for directly measuring the group-velocity difference between two orthogonally polarized wave packets propagating inside optical materials or fibers with femtosecond time resolution. This technique can be used to improve the accuracy of polarization-mode-dispersion measurement in single-mode and high-birefringence fibers, fiber sensors, and birefringent materials, including nonlinear crystals, waveguides, Pockels cells, and Faraday rotators, in the visible and IR spectra.
Summary form only given. Pairs of entangled photons display a complex quantum state that cannot be represented through a product of single-particle states. The spontaneous parametric down-conversion (SPDC) process, that takes place when a laser pulse pumps a second-order nonlinear crystal has become recently a convenient source of such nonclassical states of light in quantum optics experiments. Nonstationary effects are mainly observed when the pump pulse temporal duration is significantly shorter than the characteristic interaction time in the nonlinear crystal. We introduce a nonstationary theory of SPDC to describe the results of fourth-order quantum-interference experiments when no spectral filtering is applied to the down-converted fields. Experiments involving nonlinear SPDC crystals with three different lengths were performed. The ultraviolet laser pulses were obtained from a Ti:sapphire femtosecond laser with a second-harmonic generator. These pulses were used to pump nonlinear crystals to initiate the process of nonstationary spdc and generate orthogonally-polarized photon pairs. These pairs then went into a polarization interferometer, and the coincidence counts of the detectors at the two output ports of the interferometer were recorded.