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

Nonlinear Guided Waves and Their Applications

Nonclassical statistics of intracavity coupled quadratic nonlinear waveguides: the quantum optical dimer

Morten Bache, Yu. B. Gaĭdideĭ, Peter Leth Christiansen

Published Jan 1, 2002• 0 citations
Publisher

Abstract

Two quadratic nonlinear waveguides are immersed in a cavity suited for second-harmonic generation. The quantum equations are derived to calculate intensity correlation spectra and strong quantum violations of the classical limit is observed.
DOI
10.1364/nlgw.2002.nlmd45

Related papers

Nonclassical statistics of intracavity coupled χ(2) waveguides: The quantum optical dimer

Morten Bache, Yu. B. Gaĭdideĭ, Peter Leth Christiansen

A model is proposed where two ${\ensuremath{\chi}}^{(2)}$ nonlinear waveguides are contained in a cavity suited for second-harmonic generation. The evanescent wave coupling between the waveguides is considered as weak, and the interplay between this coupling and the nonlinear interaction within the waveguides gives rise to quantum violations of the standard quantum limit. Pronounced twin-beam behavior is observed as almost complete noise suppression in the difference as well as the sum of the waveguide intensities close to bistable transitions, self-pulsing instabilities as well as the transition from symmetric to asymmetric states. The correlations imply strong correlations and anticorrelations induced by the coupling. The violations of the standard quantum limit are particularly strong when two instabilities are competing. The results are based on the full quantum Langevin equations derived from the boson operator Hamiltonian and including cavity damping effects. The intensity correlations of the output fields are calculated semianalytically using a linearized version of the Langevin equations derived through the positive-P representation. Confirmation of the analytical results are obtained by numerical simulations of the nonlinear Langevin equations derived using the truncated Wigner representation.

arXiv:quant-ph/0205029•Physical Review A•Apr 4, 2003•23 citations

Quantum statistics and dynamics of nonlinear couplers

Jan Peřina, Jan Peřina

We investigate both codirectional and contradirectional nonlinear couplers composed of two nonlinear waveguides operating by second-harmonic generation. We take into account possible mismatches inside the waveguides and between them. We calculate the photon number distribution, its factorial moments, quadrature and integrated intensity variances and quadrature uncertainty product taking into account the effects of transmission of light between waveguides. Incident beams are assumed to be coherent, squeezed and mixed with external noise. Second-harmonic modes are assumed to be pumped with strong coherent beams. We show that non-classical behaviour of beams generated by the nonlinear waveguides can be transferred between them and controlled by linear and nonlinear mismatches. In the contradirectional regime of propagation, asymptotic non-classical states can be generated.

Journal of Modern Optics•Sep 1, 1996•29 citations

Nonclassical properties of nonlinear light beam interactions

Jan Peřina

We investigate both codirectional and contradirectional nonlinear couplers composed of two nonlinear waveguides operating by second harmonic generation. We take into account possible mismatches inside the waveguides and between them. Quantum statistical characteristics, such as photon number distribution, its factorial moments, quadrature and integrated intensity vari- ances and quadrature uncertainty product can demonstrate effects of transmission of light between waveguides. Incident beams can be assumed to be coherent, squeezed and mixed with external noise. Second harmonic modes are assumed to be pumped with strong coherent beams. Nonclassical behavior of beams generated by the nonlinear waveguides can be transferred between them and controlled by linear and nonlinear mismatches. In the contradirectional regime of propagation asymptotic nonclassical states can be generated.

17th Congress of the International Commission for Optics: Optics for Science and New Technology•Sep 1, 1996•0 citations

Photon statistics of a contradirectional nonlinear coupler

Jan Peřina, J Perina

We examine a contradirectional asymmetric nonlinear coupler composed of a linear waveguide and a nonlinear waveguide operating by second harmonic generation. For this we develop a new consistent approach to quantum contradirectional propagation. Using a short-length approximation or a strong stimulating field in the second harmonic mode, we can demonstrate an effective transfer of non-classical properties of light from nonlinear to linear waveguides analysing quadrature and integrated intensity fluctuations, photon number distribution, reduced factorial moments and uncertainty product. Effects of non-classical behaviour of incident beams and of external noise are involved.

Quantum and Semiclassical Optics Journal of the European Optical Society Part B•Oct 1, 1995•32 citations

Biphoton generation in quadratic waveguide arrays: A classical optical simulation

M. Gräfe, A. S. Solntsev, R. Keil +6 more

Quantum entanglement became essential in understanding the non-locality of quantum mechanics. In optics, this non-locality can be demonstrated on impressively large length scales, as photons travel with the speed of light and interact only weakly with their environment. Spontaneous parametric down-conversion (SPDC) in nonlinear crystals provides an efficient source for entangled photon pairs, so-called biphotons. However, SPDC can also be implemented in nonlinear arrays of evanescently coupled waveguides which allows the generation and the investigation of correlated quantum walks of such biphotons in an integrated device. Here, we analytically and experimentally demonstrate that the biphoton degrees of freedom are entailed in an additional dimension, therefore the SPDC and the subsequent quantum random walk in one-dimensional arrays can be simulated through classical optical beam propagation in a two-dimensional photonic lattice. Thereby, the output intensity images directly represent the biphoton correlations and exhibit a clear violation of a Bell-like inequality.

arXiv:1205.4085•Scientific Reports•Aug 7, 2012•46 citations

Biphoton generation in quadratic waveguide arrays: A classical optical simulation

Markus Gräfe, Alexander S. Solntsev, Robert Keil +6 more

∗ both authors contributed equally Quantum entanglement, the non-separability of a multipartite wave function, became essential in understanding the non-locality of quantum mechanics. In optics, this non-locality can be demon-strated on impressively large length scales, as photons travel with the speed of light and interact only weakly with their environment. With the discovery of spontaneous parametric down-conversion (SPDC) in nonlinear crystals, an efficient source for entangled photon pairs, so-called biphotons, be-came available. It has recently been shown that SPDC can also be implemented in nonlinear arrays of evanescently coupled waveguides which allows the generation and the investigation of correlated quantum walks of such biphotons in an integrated device. Here, we analytically and experimentally demonstrate that the biphoton degrees of freedom are entailed in an additional spatial dimension, therefore the SPDC and the subsequent quantum random walk in one-dimensional (1D) arrays can be simulated through classical optical beam propagation in a two-dimensional (2D) photonic lattice. Thereby, the output intensity images directly represent the biphoton correlations and exhibit a clear violation of a Bell-type inequality. PACS numbers: 42.50.-p, 42.82.Et, 42.65.Lm

•Aug 16, 2016•29 citations
A model is proposed where two ${\ensuremath{\chi}}^{(2)}$ nonlinear waveguides are contained in a cavity suited for second-harmonic generation. The evanescent wave coupling between the waveguides is considered as weak, and the interplay between this coupling and the nonlinear interaction within the waveguides gives rise to quantum violations of the standard quantum limit. Pronounced twin-beam behavior is observed as almost complete noise suppression in the difference as well as the sum of the waveguide intensities close to bistable transitions, self-pulsing instabilities as well as the transition from symmetric to asymmetric states. The correlations imply strong correlations and anticorrelations induced by the coupling. The violations of the standard quantum limit are particularly strong when two instabilities are competing. The results are based on the full quantum Langevin equations derived from the boson operator Hamiltonian and including cavity damping effects. The intensity correlations of the output fields are calculated semianalytically using a linearized version of the Langevin equations derived through the positive-P representation. Confirmation of the analytical results are obtained by numerical simulations of the nonlinear Langevin equations derived using the truncated Wigner representation.
We investigate both codirectional and contradirectional nonlinear couplers composed of two nonlinear waveguides operating by second-harmonic generation. We take into account possible mismatches inside the waveguides and between them. We calculate the photon number distribution, its factorial moments, quadrature and integrated intensity variances and quadrature uncertainty product taking into account the effects of transmission of light between waveguides. Incident beams are assumed to be coherent, squeezed and mixed with external noise. Second-harmonic modes are assumed to be pumped with strong coherent beams. We show that non-classical behaviour of beams generated by the nonlinear waveguides can be transferred between them and controlled by linear and nonlinear mismatches. In the contradirectional regime of propagation, asymptotic non-classical states can be generated.
We investigate both codirectional and contradirectional nonlinear couplers composed of two nonlinear waveguides operating by second harmonic generation. We take into account possible mismatches inside the waveguides and between them. Quantum statistical characteristics, such as photon number distribution, its factorial moments, quadrature and integrated intensity vari- ances and quadrature uncertainty product can demonstrate effects of transmission of light between waveguides. Incident beams can be assumed to be coherent, squeezed and mixed with external noise. Second harmonic modes are assumed to be pumped with strong coherent beams. Nonclassical behavior of beams generated by the nonlinear waveguides can be transferred between them and controlled by linear and nonlinear mismatches. In the contradirectional regime of propagation asymptotic nonclassical states can be generated.
We examine a contradirectional asymmetric nonlinear coupler composed of a linear waveguide and a nonlinear waveguide operating by second harmonic generation. For this we develop a new consistent approach to quantum contradirectional propagation. Using a short-length approximation or a strong stimulating field in the second harmonic mode, we can demonstrate an effective transfer of non-classical properties of light from nonlinear to linear waveguides analysing quadrature and integrated intensity fluctuations, photon number distribution, reduced factorial moments and uncertainty product. Effects of non-classical behaviour of incident beams and of external noise are involved.
Quantum entanglement became essential in understanding the non-locality of quantum mechanics. In optics, this non-locality can be demonstrated on impressively large length scales, as photons travel with the speed of light and interact only weakly with their environment. Spontaneous parametric down-conversion (SPDC) in nonlinear crystals provides an efficient source for entangled photon pairs, so-called biphotons. However, SPDC can also be implemented in nonlinear arrays of evanescently coupled waveguides which allows the generation and the investigation of correlated quantum walks of such biphotons in an integrated device. Here, we analytically and experimentally demonstrate that the biphoton degrees of freedom are entailed in an additional dimension, therefore the SPDC and the subsequent quantum random walk in one-dimensional arrays can be simulated through classical optical beam propagation in a two-dimensional photonic lattice. Thereby, the output intensity images directly represent the biphoton correlations and exhibit a clear violation of a Bell-like inequality.
∗ both authors contributed equally Quantum entanglement, the non-separability of a multipartite wave function, became essential in understanding the non-locality of quantum mechanics. In optics, this non-locality can be demon-strated on impressively large length scales, as photons travel with the speed of light and interact only weakly with their environment. With the discovery of spontaneous parametric down-conversion (SPDC) in nonlinear crystals, an efficient source for entangled photon pairs, so-called biphotons, be-came available. It has recently been shown that SPDC can also be implemented in nonlinear arrays of evanescently coupled waveguides which allows the generation and the investigation of correlated quantum walks of such biphotons in an integrated device. Here, we analytically and experimentally demonstrate that the biphoton degrees of freedom are entailed in an additional spatial dimension, therefore the SPDC and the subsequent quantum random walk in one-dimensional (1D) arrays can be simulated through classical optical beam propagation in a two-dimensional (2D) photonic lattice. Thereby, the output intensity images directly represent the biphoton correlations and exhibit a clear violation of a Bell-type inequality. PACS numbers: 42.50.-p, 42.82.Et, 42.65.Lm