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

Quantum Electronics and Laser Science Conference

Quantum-intensity correlations of polarizations in a nonlinear-optical fiber

T. A. B. Kennedy

Published May 12, 1991• 0 citations
OpenAlex

Abstract

The propagation of a quasimonochromatic beam in an optical fiber may be unstable owing to phase-matched four-wave mixing. The phase matching may arise in a variety of ways, and the resulting instabilities are commonly referred to as modulational instabilities. Here I consider the cross-phase-modulational (XPM) instability arising in a high birefringence optical fiber in the normal dispersion (visible) regime when the pump is polarized at 45° to the principal axes of birefringence.1,2 Orthogonally polarized sidebands are generated along these axes. Phase matching arises from a balance between dispersion and the group velocity mismatch of the sidebands and dictates that the up-shifted sideband travels on the fast axis. The sidebands result in terahertz modulation of the pump and are interesting from the point of view of optical communications. From a quantum-statistical perspective, the quantum correlations, which develop as the sidebands are generated from quantum noise, are the focus of attention here.

Related papers

Quantum theory of cross-phase-modulational instability: Twin-beam correlations in a χ(3) process

T. A. B. Kennedy

We consider the quantum correlations between fields generated through cross-phase-modulational instability in an optical fiber. Two examples of this instability are addressed, one relating to the linear-polarization eigenstates in a high-birefringence fiber, and the other to two-color propagation in a fiber. The degrees of second-order coherence of the quantum noise sidebands generated in this ${\mathrm{\ensuremath{\chi}}}^{(3)}$ process are calculated, and the violation of a classical Cauchy-Schwarz inequality and intensity-difference squeezing is reported for light transmitted by a passive filter. Around 50% intensity-difference squeezing is possible in the case of the two-color instability. This illustrates the quantum-statistical nature of the sideband correlations and how passive processing may in some circumstances help accentuate quantum correlations.

Physical Review A•Aug 1, 1991•20 citations

Polarization map of correlated sideband generation in vectorial four-wave mixing

N. L. Petrov, Alexander A. Voronin, Andrei B. Fedotov +1 more

Polarization analysis of vectorial four-wave mixing (FWM) in birefringent photonic-crystal fibers reveals physically significant tendencies in the behavior of FWM sideband correlations as a function of fiber birefringence, dispersion, and nonlinearity, as well as the pump intensity and bandwidth. Scanning over this parameter space is shown to steer vectorial FWM from largely decoupled sideband generation by individual polarization modes of the pump to FWM scenarios enabling multipartite entanglement generation.

Applied Physics Letters•May 1, 2017•10 citations

Photon pair correlations and the effect of Raman scattering noise in optical fibers

T. A. B. Kennedy, J. Stephens

The propagation of a quantized radiation field in a nonlinear optical fiber is investigated by using a quantum nonlinear Schrödinger equation with Raman scattering contributions.1 Wideband photon pair correlations generated via the optical Kerr effect and the role of group velocity dispersion and Raman scattering will be discussed. Specifically, the quantum correlations of up-shifted and downshifted sidebands in the modulational instability at terahertz frequency detuning from the pump lie outside the GAWBS region, but they are influenced by the low frequency region of the Raman gain curve, which introduces an asymmetry between the sidebands. The effects of this asymmetry on photon pair correlations and twin beams will be discussed.

Annual Meeting Optical Society of America•Jan 1, 1992•0 citations

The influence of multiple four-wave mixing in optical fiber on noise propagation

John R. Thompson

The noise properties of propagation through optical fiber are of interest in optical communications. In recent years much attention has been focused on reducing the quantum fluctuations in one of two complementary field variables below the limit associated with coherent states. Nonlinear optical processes have played a key role in the realization of such behavior. We numerically investigate the noise properties associated with competing four-wave mixing (FWM) processes in optical fiber from a classical perspective. The nonlinear interaction of two pump waves at frequencies ω1 and ω2, which produce sidebands at 2ω2–ω1 and 2ω1–ω2 by multiple FWM, is considered. By introducing known classical fluctuations at the fiber input, one can trace the evolution of the noise in the different frequency components of the FWM spectrum by generating histograms at different fiber lengths and for different input pump powers and frequency separations. Classical behavior resembling squeezing is observed under appropriate conditions.

Annual Meeting Optical Society of America•Jan 1, 1992•0 citations

Quantum propagation: Squeezing via modulational polarization instabilities in a birefringent nonlinear medium

T. A. B. Kennedy, Stefan W. Wabnitz

We calculate the spectrum of quadrature fluctuations of orthogonal polarizations of light for a beam propagating along a birefringence axis of a dispersive transparent Kerr medium. Reshaping and tuning of the spectrum is achievable by variation of the pump power or the linear birefringence: Wide-band squeezing is predicted, and its relationship to modulational polarization instabilities discussed.

Physical Review A•Jul 1, 1988•16 citations

Propagation of Photons through Optical Fiber: Spin-Orbit Interaction and Nonlinear Phase Modulation

Dashiell L. P. Vitullo

We investigate two medium-facilitated interactions between properties of light upon propagation through optical fiber. The first is interaction between the spin and intrinsic orbital angular momentum in a linear optical medium. This interaction gives rise to fine structure in the longitudinal momenta of fiber modes and manifests in rotational beating effects. We probe those beating effects experimentally in cutback experiments, where small segments are cut from the output of a fiber to probe the evolution of both output polarization and spatial orientation, and find agreement between theoretical predictions and measured behavior. \n \nThe second is nonlinear optical interaction due to cross- and self-phase modulation between the complex-valued temporal amplitude profile of pump pulses and the amplitude profiles of generated signal and idler pulses in optical fiber photon-pair sources utilizing the four-wave mixing process named modulation instability. We develop a model including the effects of these nonlinear phase modulations (NPM) describing the time-domain wave function of the output biphoton in the low-gain regime. Assuming Gaussian temporal amplitude profiles for the pump pulse, we numerically simulate the structure of the biphoton wave function, in symmetric and asymmetric group velocity matching configurations. Comparing the overlap of the joint temporal amplitudes with and without NPM indicates how good of an approximation neglecting NPM is, and we investigate the effects of NPM on the Schmidt modes. We find that effects of NPM are small on temporally separable sources utilizing symmetric group velocity matching, but appreciably change the state of temporally entangled sources with the same group velocity matching scheme. For sources designed to produce entangled biphotons, our simulations suggest that NPM increases the Schmidt number, which may increase entanglement resource availability with utilization of a phase-sensitive detection scheme. We find that NPM effects on temporally separable sources designed with asymmetric group velocity matching produce non-negligible changes in the state structure. The purity is unaffected at perfect asymmetric group velocity matching, but if the pump is detuned from the correct wavelength, the purity degrades. The largest changes to the state due to NPM occur in long fibers with long pulse durations and low repetition rates.

•Nov 21, 2016•0 citations
The propagation of a quasimonochromatic beam in an optical fiber may be unstable owing to phase-matched four-wave mixing. The phase matching may arise in a variety of ways, and the resulting instabilities are commonly referred to as modulational instabilities. Here I consider the cross-phase-modulational (XPM) instability arising in a high birefringence optical fiber in the normal dispersion (visible) regime when the pump is polarized at 45° to the principal axes of birefringence.1,2 Orthogonally polarized sidebands are generated along these axes. Phase matching arises from a balance between dispersion and the group velocity mismatch of the sidebands and dictates that the up-shifted sideband travels on the fast axis. The sidebands result in terahertz modulation of the pump and are interesting from the point of view of optical communications. From a quantum-statistical perspective, the quantum correlations, which develop as the sidebands are generated from quantum noise, are the focus of attention here.
We consider the quantum correlations between fields generated through cross-phase-modulational instability in an optical fiber. Two examples of this instability are addressed, one relating to the linear-polarization eigenstates in a high-birefringence fiber, and the other to two-color propagation in a fiber. The degrees of second-order coherence of the quantum noise sidebands generated in this ${\mathrm{\ensuremath{\chi}}}^{(3)}$ process are calculated, and the violation of a classical Cauchy-Schwarz inequality and intensity-difference squeezing is reported for light transmitted by a passive filter. Around 50% intensity-difference squeezing is possible in the case of the two-color instability. This illustrates the quantum-statistical nature of the sideband correlations and how passive processing may in some circumstances help accentuate quantum correlations.
Polarization analysis of vectorial four-wave mixing (FWM) in birefringent photonic-crystal fibers reveals physically significant tendencies in the behavior of FWM sideband correlations as a function of fiber birefringence, dispersion, and nonlinearity, as well as the pump intensity and bandwidth. Scanning over this parameter space is shown to steer vectorial FWM from largely decoupled sideband generation by individual polarization modes of the pump to FWM scenarios enabling multipartite entanglement generation.
The propagation of a quantized radiation field in a nonlinear optical fiber is investigated by using a quantum nonlinear Schrödinger equation with Raman scattering contributions.1 Wideband photon pair correlations generated via the optical Kerr effect and the role of group velocity dispersion and Raman scattering will be discussed. Specifically, the quantum correlations of up-shifted and downshifted sidebands in the modulational instability at terahertz frequency detuning from the pump lie outside the GAWBS region, but they are influenced by the low frequency region of the Raman gain curve, which introduces an asymmetry between the sidebands. The effects of this asymmetry on photon pair correlations and twin beams will be discussed.
The noise properties of propagation through optical fiber are of interest in optical communications. In recent years much attention has been focused on reducing the quantum fluctuations in one of two complementary field variables below the limit associated with coherent states. Nonlinear optical processes have played a key role in the realization of such behavior. We numerically investigate the noise properties associated with competing four-wave mixing (FWM) processes in optical fiber from a classical perspective. The nonlinear interaction of two pump waves at frequencies ω1 and ω2, which produce sidebands at 2ω2–ω1 and 2ω1–ω2 by multiple FWM, is considered. By introducing known classical fluctuations at the fiber input, one can trace the evolution of the noise in the different frequency components of the FWM spectrum by generating histograms at different fiber lengths and for different input pump powers and frequency separations. Classical behavior resembling squeezing is observed under appropriate conditions.
We investigate two medium-facilitated interactions between properties of light upon propagation through optical fiber. The first is interaction between the spin and intrinsic orbital angular momentum in a linear optical medium. This interaction gives rise to fine structure in the longitudinal momenta of fiber modes and manifests in rotational beating effects. We probe those beating effects experimentally in cutback experiments, where small segments are cut from the output of a fiber to probe the evolution of both output polarization and spatial orientation, and find agreement between theoretical predictions and measured behavior. \n \nThe second is nonlinear optical interaction due to cross- and self-phase modulation between the complex-valued temporal amplitude profile of pump pulses and the amplitude profiles of generated signal and idler pulses in optical fiber photon-pair sources utilizing the four-wave mixing process named modulation instability. We develop a model including the effects of these nonlinear phase modulations (NPM) describing the time-domain wave function of the output biphoton in the low-gain regime. Assuming Gaussian temporal amplitude profiles for the pump pulse, we numerically simulate the structure of the biphoton wave function, in symmetric and asymmetric group velocity matching configurations. Comparing the overlap of the joint temporal amplitudes with and without NPM indicates how good of an approximation neglecting NPM is, and we investigate the effects of NPM on the Schmidt modes. We find that effects of NPM are small on temporally separable sources utilizing symmetric group velocity matching, but appreciably change the state of temporally entangled sources with the same group velocity matching scheme. For sources designed to produce entangled biphotons, our simulations suggest that NPM increases the Schmidt number, which may increase entanglement resource availability with utilization of a phase-sensitive detection scheme. We find that NPM effects on temporally separable sources designed with asymmetric group velocity matching produce non-negligible changes in the state structure. The purity is unaffected at perfect asymmetric group velocity matching, but if the pump is detuned from the correct wavelength, the purity degrades. The largest changes to the state due to NPM occur in long fibers with long pulse durations and low repetition rates.