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

Microwaves

Quantum statistical properties of ideal phase sensitive receivers

W. H. Louisell, L. R. Walker, J. P. Gordon

Published Jan 1, 1963• 0 citations
Publisher

Abstract

There has been a great deal of work done in the past on, the quantum statistical properties of noise in linear amplifiers and attenuators. However, a complete statistical description of these devices for an input consisting of a signal plus Gaussian noise does not seem to be contained in the earlier work.
DOI
10.1007/978-1-349-00447-8_43

Related papers

Quantum noise properties of non-ideal optical amplifiers and attenuators

Zhimin Shi, Ksenia Dolgaleva, Robert W. Boyd

We generalize the standard quantum model (Caves 1982 Phys.Rev. D 26 1817) of the noise properties of ideal linear amplifiers to include the possibility of non-ideal behavior.We find that under many conditions the non-ideal behavior can be described simply by assuming that the internal noise source that describes the quantum noise of the amplifier is not in its ground state.We validate this model by showing that it reproduces the known predictions of two models of non-ideal amplifiers: a laser amplifier with incomplete inversion and a cascade of alternating ideal amplifiers and ideal attenuators.We also describe implications of this model for practical devices.

Journal of Optics•Nov 24, 2011•11 citations

Squeezed Quantum Fluctuations and Noise Limits in Amplifiers and Attenuators

Claire R Gilson, Stephen Mark Barnett, Stig Stenholm

Conventional amplifiers add quantum noise to a signal. Both amplifiers and attenuators lead to a reduction of the signal-to-noise ratio. We find, however, that devices exhibiting squeezed fluctuations in the gain or loss medium lead to an improved signal-to-noise ratio, in one quadrature of the output, compared to the limits associated with conventional devices. We investigate amplifier and attenuator noise properties using a simple model in which the gain or loss medium is a broad-band reservoir in a specially prepared, or ‘rigged’, state.

Journal of Modern Optics•Jun 1, 1987•25 citations

Quantum limits on noise in linear amplifiers

Carlton M. Caves

How much noise does quantum mechanics require a linear amplifier to add to a signal it processes? An analysis of narrow-band amplifiers (single-mode input and output) yields a fundamental theorem for phase-insensitive linear amplifiers; it requires such an amplifier, in the limit of high gain, to add noise which, referred to the input, is at least as large as the half-quantum of zero-point fluctuations. For phase-sensitive linear amplifiers, which can respond differently to the two quadrature phases ("$cos\ensuremath{\omega}t$" and "$sin\ensuremath{\omega}t$"), the single-mode analysis yields an amplifier uncertainty principle---a lower limit on the product of the noises added to the two phases. A multimode treatment of linear amplifiers generalizes the single-mode analysis to amplifiers with nonzero bandwidth. The results for phase-insensitive amplifiers remain the same, but for phase-sensitive amplifiers there emerge bandwidth-dependent corrections to the single-mode results. Specifically, there is a bandwidth-dependent lower limit on the noise carried by one quadrature phase of a signal and a corresponding lower limit on the noise a high-gain linear amplifier must add to one quadrature phase. Particular attention is focused on developing a multimode description of signals with unequal noise in the two quadrature phases.

Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields•Oct 15, 1982•1,723 citations

Quantum noise properties of parametric processes

Colin J. McKinstrie, M. Yu, M. G. Raymer +1 more

In this paper the quantum noise properties of phase-insensitive and phase-sensitive parametric processes are studied. Formulas for the field-quadrature and photon-number means and variances are derived, for processes that involve arbitrary numbers of modes. These quantities determine the signal-to-noise ratios associated with the direct and homo-dyne detection of optical signals. The consequences of the aforementioned formulas are described for frequency conversion, amplification, monitoring, and transmission through sequences of attenuators and amplifiers.

Optics Express•Jan 1, 2005•114 citations

Noise in phase-preserving linear amplifiers

Shashank Pandey, Jiang Zhang, Joshua Combes +1 more

The purpose of a phase-preserving linear amplifier is to make a small signal larger, so that it can be perceived by instruments incapable of resolving the original signal, while sacrificing as little as possible in signal-to-noise. Quantum mechanics limits how well this can be done: the noise added by the amplifier, referred to the input, must be at least half a quantum at the operating frequency. This well-known quantum limit only constrains the second moments of the added noise. Here we provide the quantum constraints on the entire distribution of added noise: any phasepreserving linear amplifier is equivalent to a parametric amplifier with a physical state σ for the ancillary mode; σ determines the properties of the added noise.

AIP conference proceedings•Jan 1, 2014•0 citations

Noise properties and information capacities of phase-(in)sensitive parametric amplifiers

Colin J. McKinstrie

In this tutorial, I will review the basic concepts of information theory and quantum optics. Subsequently, I will use these concepts to discuss the noise properties and information capacities of phase-insensitive and phase-sensitive parametric amplifiers.

IEEE Photonics Society Annual Meeting•Oct 1, 2011•0 citations
We generalize the standard quantum model (Caves 1982 Phys.Rev. D 26 1817) of the noise properties of ideal linear amplifiers to include the possibility of non-ideal behavior.We find that under many conditions the non-ideal behavior can be described simply by assuming that the internal noise source that describes the quantum noise of the amplifier is not in its ground state.We validate this model by showing that it reproduces the known predictions of two models of non-ideal amplifiers: a laser amplifier with incomplete inversion and a cascade of alternating ideal amplifiers and ideal attenuators.We also describe implications of this model for practical devices.
Conventional amplifiers add quantum noise to a signal. Both amplifiers and attenuators lead to a reduction of the signal-to-noise ratio. We find, however, that devices exhibiting squeezed fluctuations in the gain or loss medium lead to an improved signal-to-noise ratio, in one quadrature of the output, compared to the limits associated with conventional devices. We investigate amplifier and attenuator noise properties using a simple model in which the gain or loss medium is a broad-band reservoir in a specially prepared, or ‘rigged’, state.
How much noise does quantum mechanics require a linear amplifier to add to a signal it processes? An analysis of narrow-band amplifiers (single-mode input and output) yields a fundamental theorem for phase-insensitive linear amplifiers; it requires such an amplifier, in the limit of high gain, to add noise which, referred to the input, is at least as large as the half-quantum of zero-point fluctuations. For phase-sensitive linear amplifiers, which can respond differently to the two quadrature phases ("$cos\ensuremath{\omega}t$" and "$sin\ensuremath{\omega}t$"), the single-mode analysis yields an amplifier uncertainty principle---a lower limit on the product of the noises added to the two phases. A multimode treatment of linear amplifiers generalizes the single-mode analysis to amplifiers with nonzero bandwidth. The results for phase-insensitive amplifiers remain the same, but for phase-sensitive amplifiers there emerge bandwidth-dependent corrections to the single-mode results. Specifically, there is a bandwidth-dependent lower limit on the noise carried by one quadrature phase of a signal and a corresponding lower limit on the noise a high-gain linear amplifier must add to one quadrature phase. Particular attention is focused on developing a multimode description of signals with unequal noise in the two quadrature phases.
In this paper the quantum noise properties of phase-insensitive and phase-sensitive parametric processes are studied. Formulas for the field-quadrature and photon-number means and variances are derived, for processes that involve arbitrary numbers of modes. These quantities determine the signal-to-noise ratios associated with the direct and homo-dyne detection of optical signals. The consequences of the aforementioned formulas are described for frequency conversion, amplification, monitoring, and transmission through sequences of attenuators and amplifiers.
The purpose of a phase-preserving linear amplifier is to make a small signal larger, so that it can be perceived by instruments incapable of resolving the original signal, while sacrificing as little as possible in signal-to-noise. Quantum mechanics limits how well this can be done: the noise added by the amplifier, referred to the input, must be at least half a quantum at the operating frequency. This well-known quantum limit only constrains the second moments of the added noise. Here we provide the quantum constraints on the entire distribution of added noise: any phasepreserving linear amplifier is equivalent to a parametric amplifier with a physical state σ for the ancillary mode; σ determines the properties of the added noise.