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

Annual Meeting Optical Society of America

Squeezed solitons: quantum and thermal noise effects

Robert M. Shelby, M. Rosenbluh, P. D. Drummond, S. J. Carte

Published Jan 1, 1991• 0 citations
Publisher

Abstract

Optical solitons are pulses that propagate in optical fibers without temporal or spectral distortion, owing to balancing of the second-order dispersion of the refractive index by nonlinear self-phase modulation induced by the intensity-dependent refractive index. Classically, this stationary distortion-free propagation only requires the proper choice of pulse width and shape for a given pulse energy. However, quantum fluctuations do not undergo stationary propagation but rather evolve due to dispersion and self-phase modulation. As a soliton pulse propagates, zero-point or vacuum noise associated with the pulse evolves into squeezed noise. Vacuum fluctuations are responsible for the fundamental detector noise floor known as the shot noise limit. Reduction of the noise in the detection of squeezed soliton pulses has achieved a noise level 34% below this limit. In optical fibers, thermal fluctuation of the refractive index limit the noise reduction that can be achieved by adding phase fluctuations in excess of the vacuum noise. At low frequencies thermal noise originates from local structural dynamics of fused silica which produces a 1/f power spectrum and from guided acoustic wage Brillouin scattering which modulates the refractive index at frequencies characteristic of the fiber structure. The bandwidth of these fluctuations is ~2 GHz; and for soliton pulses with spectral bandwidth much >2 GHz, we have shown that this noise can be made insignificant. For very short pulses, however, noise from Raman scattering must be considered. Recent calculations incorporating this noise mechanism are compared with experiment.

DOI
10.1364/oam.1991.mf2

Related papers

Squeezing of optical solitons

Robert M. Shelby, M. Rosenbluh

Optical solitons are pulses that propagate in optical fibers without temporal or spectral distortion, owing to balancing of the second-order dispersion of the refractive index by nonlinear self-phase modulation induced by the intensity-dependent refractive index. Classically, this stationary, distortion-free propagation requires only the proper choice of pulse width and shape for a given pulse energy. However, quantum mechanical zero-point fluctuations of the amplitude and phase of the optical pulse limit the precision with which this pulse shape can be produced. These quantum fluctuations do not undergo stationary propagation but, rather, evolve because of dispersion and self-phase modulation, As a soliton pulse propagates, this zero-point or vacuum noise associated with the pulse evolves into squeezed noise owing to self-phase modulation in the fiber.1,2

Quantum Electronics and Laser Science Conference•May 12, 1991•0 citations

Quantum noise and thermal noise in optical soliton propagation

Robert M. Shelby, E. H. Whittaker, P. D. Drummond +2 more

Classical optical solitons propagate in optical fibers without temporal or spectral distortion as a result of a balance between phase shifts due to group velocity dispersion and those due to nonlinear self-phase modulation. This balance is achieved by the proper choice of pulse shape and duration for a given pulse energy. The quantum fluctuations associated with a coherent soliton do not undergo stationary propagation, however, and a number of effects are predicted, including the evolution of vacuum noise associated with the input coherent pulse into squeezed fluctuations and the temporal spreading of the soliton pulse because of dispersion acting on quantum fluctuations of the pulse frequency.

Quantum Electronics and Laser Science Conference•May 10, 1992•0 citations

Quantum and thermal noise of solitons in optical fibers

P. D. Drummond, S. J. Carter

We develop a quantum theory of propagation in dispersive nonlinear media via a quantized field theory and a coherent state expansion. The resulting stochastic nonlinear Schrodinger equation includes both quantum fluctuations and thermal noise due to refractive-index fluctuations in the medium. The theory can describe either cw propagation with dispersion or soliton propagation. In the cw case, enhanced squeezing occurs with anomalous dispersion. This is reduced by thermal noise, just as it is in the normal dispersion case. The noise-induced reduction in squeezing is more severe with normal dispersion owing to the intrinsic lack of phase matching in the normal dispersion regime. With anomalous dispersion, the cancellation of nonlinear by linear dispersion allows squeezing to occur over a wide bandwidth even in the presence of thermal fluctuations. Our theory is also able to treat soliton propagation in the anomalous dispersion case. A substantial degree of pulsed squeezing is obtained, and we point out that an optimal detection scheme requires a pulsed local oscillator. Results for the effects of thermal noise on soliton propagation are presented, in which case improvement is obtained by reducing the soliton time duration.

Annual Meeting Optical Society of America•Jan 1, 1987•0 citations

Hybrid squeezing of solitonic resonant radiation in photonic crystal fibers

Truong X. Tran, Fabio Biancalana

Squeezing is a fundamental quantum optical phenomenon - induced by various nonlinear optical processes - in which a special state of the electromagnetic field is generated, for which quantum noise fluctuations are reduced below the shot noise level for certain frequency ranges. Two qualitatively different kinds of squeezing are currently known to take place in optical fibers. The first is the four-wave mixing (FWM) induced quadrature squeezing, in which an intense continuous wave (CW) pump initiates a spontaneous emission of signal and idler waves from vacuum fluctuations at symmetric detunings from the pump. The noise components at the signal and idler frequencies become correlated via the fiber nonlinearity, leading to a reduction of the noise power spectrum below the shot noise level. All the waves participating to the FWM-induced squeezing are monochromatic waves. The second kind of squeezing is the so called self-phase modulation (SPM) induced squeezing, in which the spectral components of an intense short pulse in a coherent state become correlated via the SPM during propagation. We demonstrate theoretically that a third kind of squeezing is possible in optical fibers, in which the noise spectrum of the quasi-monochromatic resonant radiation (RR) emitted by optical solitons when subject to perturbations shows evidence of photon correlation and a reduction of noise below the shot-noise level.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•May 1, 2011•2 citations

Use of longer soliton pulses to reduce Raman noise in fibre squeezing

M. Tacey, Joel Frederick Corney

A source of quantum noise in a non-linear optical medium is the coupling of photons with thermal phonons, called the Raman effect. This noise source sets the lower limit of squeezing in the polarisation variables for ultrashort pulses. Increasing the soliton pulse width reduces the coupling between photons and phonons by decreasing the overlap of the pulse spectrum and the Raman frequency response, which is specific to the medium. We investigate the dependence of squeezing on the soliton pulse width, to determine if improvements in squeezing result from longer pulses. We numerically solve a stochastic nonlinear Schrodinger equation with extra nonlinear terms for Raman effect (derived within the truncated Wigner approach), for a 3M FS-PM 7811 silica fibre using the pde solver XMDS 2.0. Computational efficiency was improved by use of a single-Lorentzian approximation for the Raman gain profile. Results show that squeezing can be improved for longer pulse widths. However, there is a tradeoff between the Raman effects and the classical phase noise due to guided acoustic wave Brillouin scattering.

•Aug 1, 2011•0 citations

Use of Longer Soliton Pulses to Reduce Raman Noise in Fibre Squeezing

M. Tacey, Joel Frederick Corney

A source of quantum noise in a non-linear optical medium is the coupling of photons with thermal phonons, called the Raman effect. This noise source sets the lower limit of squeezing in the polarisation variables for ultrashort pulses. Increasing the soliton pulse width reduces the coupling between photons and phonons by decreasing the overlap of the pulse spectrum and the Raman frequency response, which is specific to the medium. We investigate the dependence of squeezing on the soliton pulse width, to determine if improvements in squeezing result from longer pulses. We numerically solve a stochastic nonlinear Schrödinger equation with extra nonlinear terms for Raman effect (derived within the truncated Wigner approach), for a 3M FS-PM7811 silica fibre using the pde solver XMDS 2.0. Computational efficiency was improved by use of a single-Lorentzian approximation for the Raman gain profile. Results show that squeezing can be improved for longer pulse widths. However, there is a tradeoff between the Raman effects and the classical phase noise due to guided acoustic wave Brillouin scattering.

•Jan 1, 2011•1 citation
Optical solitons are pulses that propagate in optical fibers without temporal or spectral distortion, owing to balancing of the second-order dispersion of the refractive index by nonlinear self-phase modulation induced by the intensity-dependent refractive index. Classically, this stationary distortion-free propagation only requires the proper choice of pulse width and shape for a given pulse energy. However, quantum fluctuations do not undergo stationary propagation but rather evolve due to dispersion and self-phase modulation. As a soliton pulse propagates, zero-point or vacuum noise associated with the pulse evolves into squeezed noise. Vacuum fluctuations are responsible for the fundamental detector noise floor known as the shot noise limit. Reduction of the noise in the detection of squeezed soliton pulses has achieved a noise level 34% below this limit. In optical fibers, thermal fluctuation of the refractive index limit the noise reduction that can be achieved by adding phase fluctuations in excess of the vacuum noise. At low frequencies thermal noise originates from local structural dynamics of fused silica which produces a 1/f power spectrum and from guided acoustic wage Brillouin scattering which modulates the refractive index at frequencies characteristic of the fiber structure. The bandwidth of these fluctuations is ~2 GHz; and for soliton pulses with spectral bandwidth much >2 GHz, we have shown that this noise can be made insignificant. For very short pulses, however, noise from Raman scattering must be considered. Recent calculations incorporating this noise mechanism are compared with experiment.
Optical solitons are pulses that propagate in optical fibers without temporal or spectral distortion, owing to balancing of the second-order dispersion of the refractive index by nonlinear self-phase modulation induced by the intensity-dependent refractive index. Classically, this stationary, distortion-free propagation requires only the proper choice of pulse width and shape for a given pulse energy. However, quantum mechanical zero-point fluctuations of the amplitude and phase of the optical pulse limit the precision with which this pulse shape can be produced. These quantum fluctuations do not undergo stationary propagation but, rather, evolve because of dispersion and self-phase modulation, As a soliton pulse propagates, this zero-point or vacuum noise associated with the pulse evolves into squeezed noise owing to self-phase modulation in the fiber.1,2
Classical optical solitons propagate in optical fibers without temporal or spectral distortion as a result of a balance between phase shifts due to group velocity dispersion and those due to nonlinear self-phase modulation. This balance is achieved by the proper choice of pulse shape and duration for a given pulse energy. The quantum fluctuations associated with a coherent soliton do not undergo stationary propagation, however, and a number of effects are predicted, including the evolution of vacuum noise associated with the input coherent pulse into squeezed fluctuations and the temporal spreading of the soliton pulse because of dispersion acting on quantum fluctuations of the pulse frequency.
We develop a quantum theory of propagation in dispersive nonlinear media via a quantized field theory and a coherent state expansion. The resulting stochastic nonlinear Schrodinger equation includes both quantum fluctuations and thermal noise due to refractive-index fluctuations in the medium. The theory can describe either cw propagation with dispersion or soliton propagation. In the cw case, enhanced squeezing occurs with anomalous dispersion. This is reduced by thermal noise, just as it is in the normal dispersion case. The noise-induced reduction in squeezing is more severe with normal dispersion owing to the intrinsic lack of phase matching in the normal dispersion regime. With anomalous dispersion, the cancellation of nonlinear by linear dispersion allows squeezing to occur over a wide bandwidth even in the presence of thermal fluctuations. Our theory is also able to treat soliton propagation in the anomalous dispersion case. A substantial degree of pulsed squeezing is obtained, and we point out that an optimal detection scheme requires a pulsed local oscillator. Results for the effects of thermal noise on soliton propagation are presented, in which case improvement is obtained by reducing the soliton time duration.
Squeezing is a fundamental quantum optical phenomenon - induced by various nonlinear optical processes - in which a special state of the electromagnetic field is generated, for which quantum noise fluctuations are reduced below the shot noise level for certain frequency ranges. Two qualitatively different kinds of squeezing are currently known to take place in optical fibers. The first is the four-wave mixing (FWM) induced quadrature squeezing, in which an intense continuous wave (CW) pump initiates a spontaneous emission of signal and idler waves from vacuum fluctuations at symmetric detunings from the pump. The noise components at the signal and idler frequencies become correlated via the fiber nonlinearity, leading to a reduction of the noise power spectrum below the shot noise level. All the waves participating to the FWM-induced squeezing are monochromatic waves. The second kind of squeezing is the so called self-phase modulation (SPM) induced squeezing, in which the spectral components of an intense short pulse in a coherent state become correlated via the SPM during propagation. We demonstrate theoretically that a third kind of squeezing is possible in optical fibers, in which the noise spectrum of the quasi-monochromatic resonant radiation (RR) emitted by optical solitons when subject to perturbations shows evidence of photon correlation and a reduction of noise below the shot-noise level.
A source of quantum noise in a non-linear optical medium is the coupling of photons with thermal phonons, called the Raman effect. This noise source sets the lower limit of squeezing in the polarisation variables for ultrashort pulses. Increasing the soliton pulse width reduces the coupling between photons and phonons by decreasing the overlap of the pulse spectrum and the Raman frequency response, which is specific to the medium. We investigate the dependence of squeezing on the soliton pulse width, to determine if improvements in squeezing result from longer pulses. We numerically solve a stochastic nonlinear Schrodinger equation with extra nonlinear terms for Raman effect (derived within the truncated Wigner approach), for a 3M FS-PM 7811 silica fibre using the pde solver XMDS 2.0. Computational efficiency was improved by use of a single-Lorentzian approximation for the Raman gain profile. Results show that squeezing can be improved for longer pulse widths. However, there is a tradeoff between the Raman effects and the classical phase noise due to guided acoustic wave Brillouin scattering.
A source of quantum noise in a non-linear optical medium is the coupling of photons with thermal phonons, called the Raman effect. This noise source sets the lower limit of squeezing in the polarisation variables for ultrashort pulses. Increasing the soliton pulse width reduces the coupling between photons and phonons by decreasing the overlap of the pulse spectrum and the Raman frequency response, which is specific to the medium. We investigate the dependence of squeezing on the soliton pulse width, to determine if improvements in squeezing result from longer pulses. We numerically solve a stochastic nonlinear Schrödinger equation with extra nonlinear terms for Raman effect (derived within the truncated Wigner approach), for a 3M FS-PM7811 silica fibre using the pde solver XMDS 2.0. Computational efficiency was improved by use of a single-Lorentzian approximation for the Raman gain profile. Results show that squeezing can be improved for longer pulse widths. However, there is a tradeoff between the Raman effects and the classical phase noise due to guided acoustic wave Brillouin scattering.