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 A

Double transverse wave-vector correlations in photon pairs generated by spontaneous parametric down-conversion pumped by Bessel-Gauss beams

Verónica Vicuña-Hernández, J. Santiago, Yasser Jerónimo-Moreno, Roberto Ramírez-Alarcón, Héctor Cruz-Ramírez, Alfred B. U’Ren, Rocío Jáuregui

Published Dec 30, 2016• 7 citations
Publisher

Abstract

We present an experimental and theoretical study of type I, frequency-degenerate spontaneous parametric down-conversion (SPDC) with a Bessel-Gauss pump in which we include both paraxial and nonparaxial pump beam configurations. We present measurements of the SPDC angular spectrum (AS), of the conditional angular spectrum (CAS) of signal-mode single photons as heralded by the detection of an idler photon, and of the transverse wave-vector signal-idler correlations (TWC). We show that as the pump is made increasingly nonparaxial, the AS acquires a nonconcentric double-cone structure, with the CAS shape depending on the azimuthal location of the heralding detector, while the signal-idler wave-vector correlation region splits into characteristic doublet stripes, representing as yet unexplored nontrivial, nonlocal quantum correlations between the signal and idler photons. Our work provides further understanding of SPDC with a particular class of structured pump beams, and we believe that the controlled presence of double wave-vector correlations represents an interesting resource for photon-pair quantum-state engineering.

DOI
10.1103/physreva.94.063863

Related papers

Spatial control of spontaneous parametric down-conversion photon pairs through the use of apertured Bessel-Gauss pump beams

Dalia Gutiérrez-López, Mónica Maldonado-Terrón, Raul Josue Hernandez +5 more

We demonstrate, both experimentally and theoretically, a method that allows us to modify the spatial properties of photon pairs produced by the process of spontaneous parametric down-conversion (SPDC) with an apertured, zeroth-order Bessel-Gauss beam. Concentrating on the use of a half-plane aperture, we show that the phase-matching conditions for non-paraxial pump beams can be controlled by simply changing the aperture orientation. Partially blocking the pump beam, leads to a selection of either one of two individual cones that form a dual-cone SPDC angular spectrum, or a portion of both of them. We can likewise determine the shape and orientation of the conditional angular spectrum. This control of the SPDC spatial properties could be useful for quantum information processing protocols.

Physical Review A•Jul 2, 2019•7 citations

A 2-D study of intensity correlation of single photon pairs in spontaneous parametric down conversion

E. R. Eliel, Sumant S. R. Oemrawsingh, W. J. van Drunen +1 more

Summary form only given. Entangled photons are the workhorse of quantum information technology and cryptography. So far, the emphasis has been on entanglement of the polarization state (for type II down conversion), or of the wave vectors of the degenerate signal and idler pair (for type I down conversion). A subject of current interest is entanglement in the spatial domain, i.e. nontrivial, spatially extended, correlation between signal and idler. A prime example of this being the discussion regarding the conservation and entanglement of orbital angular momentum in spontaneous parametric down conversion. We report our very first measurements of the signal-idler correlation in type I down conversion, employing a frequency-doubled femtosecond Ti:sapphire laser as our source of pump photons, and a fourth generation intensified CCD as our "multi-element single-photon detector" With pump pulses at /spl lambda/ = 400 nm of approximately 2 nJ energy and 250 fs duration directed at a 0.5 mm long BBO crystal we detect roughly one pair in every four frames.

Quantum Electronics and Laser Science Conference•Nov 13, 2002•0 citations

On-demand generation of propagation-invariant photons with orbital angular momentum

Yasser Jerónimo-Moreno, Rocío Jáuregui

We study the generation of propagation invariant photons with orbital angular momentum by spontaneous parametric down conversion (SPDC) using a Bessel-Gauss pump beam. The angular and conditional angular spectra are calculated for an uniaxial crystal optimized for type I SPDC with standard Gaussian pump beams. It is shown that, as the mean value of the magnitude of the transverse wave vector of the pump beam increases, the emission cone is deformed into two non-coaxial cones that touch each other along a line determined by the orientation of the optical axis of the nonlinear crystal. At this location, the conditional spectrum becomes maximal for a pair of photons, one of which is best described by a Gaussian-like photon with a very small transverse wave vector, and the other a Bessel-Gauss photon with a distribution of transverse wave vectors similar in amplitude to that of the incident pump beam. A detailed analysis is then performed of the angular momentum content of SPDC photons by the evaluation of the corresponding transition amplitudes. As a result, we obtain conditions for the generation of heralded single photons which are approximately propagation invariant and have orbital angular momentum. A discussion is given about the difficulties in the interpretation of the results in terms of conservation of optical orbital angular momentum along the vector normal to the crystal surface. The angular spectra and the conditional angular spectra are successfully compared with available experimental data recently reported in the literature.

arXiv:1403.5474•Physical Review A•Jul 23, 2014•7 citations

Azimuthal correlation of photon pairs generated in spontaneous parametric down-conversion

Vygandas Jarutis, Saulius Juodkazis, Vygantas Mizeikis +1 more

Correlations between the entire conical spatial modes of signal and idler beams in a type II spontaneous parametric down-conversion (SPDC) under ultrashort pulse pumping are examined experimentally and theoretically. Statistical properties and theoretical analysis of ``path-entangled'' states formed using these beams suggest that the quantum state of SPDC photon pairs cannot be represented by a pure ensemble of identically prepared pairs.

Physical Review A•Oct 30, 2007•0 citations

The orbital angular momentum of photons in noncollinear spontaneous parametric downconversion

Juan P. Torres, Clara I. Osorio, Gabriel Molina‐Terriza +1 more

We elucidate the paraxial orbital angular momentum of entangled photon pairs generated by spontaneous parametric down-conversion (SPDC) in different non-collinear geometries. To date, most investigations addressed SPDC in nearly collinear phase-matching geometries, where the pump, the signal and idler photons propagate coaxially almost along the same direction. However, non-collinear geometries introduce a variety of new features. The OAM of the entangled photons strongly depend on the propagation direction of the photons. Here we show that locally paraxial measurements of the OAM conducted with entangled photons generated in non collinear geometries, they do not comply with the known selection rules for the spiral index of the pump, signal and idler mode functions (Mair et al., Nature 412, 313 (2001)). In particular, we find the orbital angular momentum of entangled pairs generated in purely transverse-emitting configurations, where the entangled photons counter-propagate perpendicularly to the direction of propagation of the pump beam. In transverse emitting configurations, the spatial shape of the down converted in one transverse dimensions strongly depends on the corresponding spatial shape of the input pump beam, while in the other transverse dimension, the shape is tailored by the longitudinal phase matching. The spatial walk-off of all interacting waves in the parametric process also determines the OAM content of the down-converted photons, and here its influence is also revealed.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Mar 14, 2005•0 citations

Effects of crystal length on the angular spectrum of spontaneous parametric downconversion photon pairs

Roberto Ramírez-Alarcón, H Cruz-Ramírez, A B U’Ren

We present a theoretical and experimental analysis of the joint effects of the transverse electric field distribution and of the nonlinear crystal characteristics on the properties of photon pairs generated by spontaneous parametric downconversion (SPDC). While it is known that for a sufficiently short crystal the pump electric field distribution fully determines the joint signal–idler properties, for longer crystals the nonlinear crystal properties also play an important role. In this paper we present experimental measurements of the angular spectrum (AS) and of the conditional angular spectrum (CAS) of photon pairs produced by SPDC, carried out through spatially resolved photon counting. In our experiment we control whether or not the source operates in the short-crystal regime through the degree of pump focusing, and explicitly show how the AS and CAS measurements differ in these two regimes. Our theory provides an understanding of the boundary between these two regimes and also predicts the corresponding differing behaviors.

arXiv:1306.4903•Laser Physics•Apr 10, 2013•48 citations
We present an experimental and theoretical study of type I, frequency-degenerate spontaneous parametric down-conversion (SPDC) with a Bessel-Gauss pump in which we include both paraxial and nonparaxial pump beam configurations. We present measurements of the SPDC angular spectrum (AS), of the conditional angular spectrum (CAS) of signal-mode single photons as heralded by the detection of an idler photon, and of the transverse wave-vector signal-idler correlations (TWC). We show that as the pump is made increasingly nonparaxial, the AS acquires a nonconcentric double-cone structure, with the CAS shape depending on the azimuthal location of the heralding detector, while the signal-idler wave-vector correlation region splits into characteristic doublet stripes, representing as yet unexplored nontrivial, nonlocal quantum correlations between the signal and idler photons. Our work provides further understanding of SPDC with a particular class of structured pump beams, and we believe that the controlled presence of double wave-vector correlations represents an interesting resource for photon-pair quantum-state engineering.
We demonstrate, both experimentally and theoretically, a method that allows us to modify the spatial properties of photon pairs produced by the process of spontaneous parametric down-conversion (SPDC) with an apertured, zeroth-order Bessel-Gauss beam. Concentrating on the use of a half-plane aperture, we show that the phase-matching conditions for non-paraxial pump beams can be controlled by simply changing the aperture orientation. Partially blocking the pump beam, leads to a selection of either one of two individual cones that form a dual-cone SPDC angular spectrum, or a portion of both of them. We can likewise determine the shape and orientation of the conditional angular spectrum. This control of the SPDC spatial properties could be useful for quantum information processing protocols.
Summary form only given. Entangled photons are the workhorse of quantum information technology and cryptography. So far, the emphasis has been on entanglement of the polarization state (for type II down conversion), or of the wave vectors of the degenerate signal and idler pair (for type I down conversion). A subject of current interest is entanglement in the spatial domain, i.e. nontrivial, spatially extended, correlation between signal and idler. A prime example of this being the discussion regarding the conservation and entanglement of orbital angular momentum in spontaneous parametric down conversion. We report our very first measurements of the signal-idler correlation in type I down conversion, employing a frequency-doubled femtosecond Ti:sapphire laser as our source of pump photons, and a fourth generation intensified CCD as our "multi-element single-photon detector" With pump pulses at /spl lambda/ = 400 nm of approximately 2 nJ energy and 250 fs duration directed at a 0.5 mm long BBO crystal we detect roughly one pair in every four frames.
We study the generation of propagation invariant photons with orbital angular momentum by spontaneous parametric down conversion (SPDC) using a Bessel-Gauss pump beam. The angular and conditional angular spectra are calculated for an uniaxial crystal optimized for type I SPDC with standard Gaussian pump beams. It is shown that, as the mean value of the magnitude of the transverse wave vector of the pump beam increases, the emission cone is deformed into two non-coaxial cones that touch each other along a line determined by the orientation of the optical axis of the nonlinear crystal. At this location, the conditional spectrum becomes maximal for a pair of photons, one of which is best described by a Gaussian-like photon with a very small transverse wave vector, and the other a Bessel-Gauss photon with a distribution of transverse wave vectors similar in amplitude to that of the incident pump beam. A detailed analysis is then performed of the angular momentum content of SPDC photons by the evaluation of the corresponding transition amplitudes. As a result, we obtain conditions for the generation of heralded single photons which are approximately propagation invariant and have orbital angular momentum. A discussion is given about the difficulties in the interpretation of the results in terms of conservation of optical orbital angular momentum along the vector normal to the crystal surface. The angular spectra and the conditional angular spectra are successfully compared with available experimental data recently reported in the literature.
We elucidate the paraxial orbital angular momentum of entangled photon pairs generated by spontaneous parametric down-conversion (SPDC) in different non-collinear geometries. To date, most investigations addressed SPDC in nearly collinear phase-matching geometries, where the pump, the signal and idler photons propagate coaxially almost along the same direction. However, non-collinear geometries introduce a variety of new features. The OAM of the entangled photons strongly depend on the propagation direction of the photons. Here we show that locally paraxial measurements of the OAM conducted with entangled photons generated in non collinear geometries, they do not comply with the known selection rules for the spiral index of the pump, signal and idler mode functions (Mair et al., Nature 412, 313 (2001)). In particular, we find the orbital angular momentum of entangled pairs generated in purely transverse-emitting configurations, where the entangled photons counter-propagate perpendicularly to the direction of propagation of the pump beam. In transverse emitting configurations, the spatial shape of the down converted in one transverse dimensions strongly depends on the corresponding spatial shape of the input pump beam, while in the other transverse dimension, the shape is tailored by the longitudinal phase matching. The spatial walk-off of all interacting waves in the parametric process also determines the OAM content of the down-converted photons, and here its influence is also revealed.
We present a theoretical and experimental analysis of the joint effects of the transverse electric field distribution and of the nonlinear crystal characteristics on the properties of photon pairs generated by spontaneous parametric downconversion (SPDC). While it is known that for a sufficiently short crystal the pump electric field distribution fully determines the joint signal–idler properties, for longer crystals the nonlinear crystal properties also play an important role. In this paper we present experimental measurements of the angular spectrum (AS) and of the conditional angular spectrum (CAS) of photon pairs produced by SPDC, carried out through spatially resolved photon counting. In our experiment we control whether or not the source operates in the short-crystal regime through the degree of pump focusing, and explicitly show how the AS and CAS measurements differ in these two regimes. Our theory provides an understanding of the boundary between these two regimes and also predicts the corresponding differing behaviors.