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Matteo G. A. Paris

Publications and source records attributed to Matteo G. A. Paris.

314 records · Page 18Linked to original sources
arXiv1998

Generation of phase-coherent states

An interaction scheme involving nonlinear $χ^{(2)}$ media is suggested for the generation of phase-coherent states (PCS). The setup is based on parametric amplification of vacuum followed by up-conversion of the resulting twin-beam. The involved nonlinear interactions are studied by the exact numerical diagonalization. An experimentally achievable working regime to approximate PCS with high conversion rate is given, and the validity of parametric approximation is discussed.

quant-ph↗
arXiv1998

Quantum Binary Decision for Driven Harmonic Oscillator

We address the problem of determining whether or not a harmonic oscillator has been perturbed by an external force. Quantum detection and estimation theory has been used in devising optimum measurement schemes. Detection probability has been evaluated for different initial state preparations of oscillator. The corresponding lower bounds on minimum detectable perturbation intensity has been evaluated and a general bound for random phase perturbation has been also induced.

quant-ph↗
arXiv1997

Added noise in homodyne measurement of field-observables

Homodyne tomography provides a way for measuring generic field-operators. Here we analyze the determination of the most relevant quantities: intensity, field, amplitude and phase. We show that tomographic measurements are affected by additional noise in comparison with the direct detection of each observable by itself. The case of of coherent states has been analyzed in details and earlier estimations of tomographic precision are critically discussed.

quant-ph↗
arXiv1996

Two-photocurrent devices

Heterodyne, eight-port homodyne and six-port homodyne detectors belong to the class of two-photocurrent devices. Their full equivalence in probing radiation field has been proved both for ideal and not fully efficient photodetectors. The output probability distribution has been also evaluated for a generic probe mode.

quant-ph↗
arXiv1996

Interferometry as a binary decision problem

Binary decision theory has been applied to the general interferometric problem. Optimal detection scheme-according to the Neyman-Pearson criterion-has been considered for different phase-enhanced states of radiation field, and the corresponding bounds on minimum detectable phase shift has been evaluated. A general bound on interferometric precision has been also obtained in terms of photon number fluctuations of the signal mode carrying the phase information.

quant-ph↗
arXiv1995

Quantum state measurement by realistic heterodyne detection

The determination of the quantum properties of a single mode radiation field by heterodyne or double homodyne detection is studied. The realistic case of not fully efficient photodetectors is considered. It is shown that a large amount of quite {\em precise} information is avalaible whereas the completeness of such information is also discussed. Some examples are given and the special case of states expressed as a finite superposition of number states is considered in some detail.

quant-ph↗
arXiv1995

Squeezed Vacuum Interferometry

A high-sensitive interferometric scheme is presented. It is based on homodyne detection and squeezed vacuum phase properties. The resulting phase sensitivity scales as $δϕ\simeq {1/4} \bar{n}^{-1}$ with respect to input photons number.

quant-ph↗