© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Quantum Interference of Correlated Boson Fields: Homodyne and Heterodyne Optical Interferometry below the Shot Noise

Sheng Feng

Published May 1, 2005• 0 citations

Abstract

Quantum interference of twin optical beams, a typical example of correlated boson fields, is of great interest from the viewpoint of both fundamental and applied physics. Intensity correlated optical beams and their quantum interference bring the possibility of performing sub-shot-noise interferometry experiments which yield high-sensitivity in practical applications. A type-II doubly resonant optical parametric oscillator (OPO) has been built for research in quantum optics, to provide a source of ultrastable quantum correlated (twin) optical beams with continuously tunable frequency difference from zero up to several THz. Three servo loops have been built to control the frequency difference of the twin optical beams and sub-hertz stability has been achieved for frequency difference up to 100MHz. In particular, frequency degenerate twin beams are indistinguishable macroscopic quantum systems. A series of experimental results has been produced with these OPO-generated ultrastable twin beams: the observation of the generalized Hong-Ou-Mandel interference of untrastable twin optical beams, sub-shot-noise homodyne interferometry, and sub-shot-noise heterodyne polarimetry. Note: Abstract extracted from PDF text

DOI: 10.18130/v3g51r

Related papers

Quantum noise of ultrastable bright twin beams

Olivier Pfister, Sheng Feng

We investigate experimentally the number and phase quantum noises of the light emitted by an ultrastable nondegenerate optical parametric oscillator (OPO) above threshold. Strong intensity correlations at the photon level -- number-difference squeezing or twin beams -- have already been observed by several groups. We have recently observed the twin-beam interference of a classically phase-locked OPO and have shown that the phase-difference is antisqueezed, as expected from the number-phase Heisenberg (in)equality. In this paper we describe the realization of a stable classical measurement of the joint quadratures of an OPO, as part of our ongoing effort to generate ultrastable EPR light beams simultaneously squeezed in number difference and phase sum.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 25, 2004•0 citations

Sub-shot-noise heterodyne polarimetry

Sheng Feng, Olivier Pfister

We report an experimental demonstration of a heterodyne polarization rotation measurement with a noise floor 4.8 dB below the optical shot noise by use of classically phase-locked quantum twin beams emitted above threshold by an ultrastable type II Na:KTP cw optical parametric oscillator. We believe that this is the largest noise reduction achieved to date in optical phase-difference measurements.

arXiv:quant-ph/0406031•Optics Letters•Dec 1, 2004•16 citations

Quantum Interference of Ultrastable Twin Optical Beams

Sheng Feng, Olivier Pfister

We report the first measurement of the quantum phase-difference noise of an ultrastable nondegenerate optical parametric oscillator that emits twin beams classically phase locked at exact frequency degeneracy. The measurement illustrates the property of a lossless balanced beam splitter to convert number-difference squeezing into phase-difference squeezing, and thus provides indirect evidence for Heisenberg-limited interferometry using twin beams. This experiment is a generalization of the Hong-Ou-Mandel interference effect for continuous variables and constitutes a milestone towards continuous-variable entanglement of bright, ultrastable nondegenerate beams.

arXiv:quant-ph/0310002•Physical Review Letters•May 21, 2004•43 citations

Twin beams, squeezed light, and their uses

E. Giacobino, Jerome C. Mertz, Claude Fabre +2 more

In recent years, several experiments have established the optical parametric oscillator (OPO) as a practical source of highly correlated twin beams. These beams have an intensity difference noise substantially below the associated shot noise, for noise frequencies within the OPO cavity bandwidth. They present the additional feature of being laserlike and intense, making them convenient for experimental applications. Refinements on our OPO characteristics and photodiode efficiencies have yielded a reduction of the noise power in the intensity difference of 86% below the shot noise level.1 A first use of twin beams is the production of a single light beam having an intensity squeezed noise. This can be achieved by monitoring the intensity of one beam with a photodiode and using this information to control the intensity fluctuations of the second beam with an electrooptic modulator.2 Other applications to high sensitivity spectroscopic measurements such as linear and nonlinear absorption or dispersion can now be considered for practical use.

Annual Meeting Optical Society of America•Jan 1, 1991•0 citations

Sub-shot-noise high-sensitivity spectroscopy with optical parametric oscillator twin beams

P. H. Souto Ribeiro, Catherine Schwob, Agnès Maître +1 more

Nondegenerate optical parametric oscillators generate above-threshold signal and idler beams that have intensity fluctuations correlated at the quantum level (twin beams). We describe what is to our knowledge the first high-sensitivity spectroscopy experiment using twin beams emitted by a cw optical parametric oscillator: a very weak two-photon absorption signal, in the 10(-7) range, is recorded on the 4S(1/2)-5S(1/2) transition of atomic potassium with a noise background that is reduced by 1.9 dB with respect to the shot-noise limit of the light used in the experiment.

Optics Letters•Dec 15, 1997•119 citations

Quantum interference of ultrastable twin beams

Sheng Feng, Olivier Pfister

We report the first measurement of the quantum phase-difference noise of an ultrastable nondegenerate optical parametric oscillator that emits twin beams classically phase-locked at exact frequency degeneracy. The measurement illustrates the property of a lossless balanced beam-splitter to convert number-difference squeezing into phase-difference squeezing and, thus, provides indirect evidence for Heisenberg-limited interferometry using twin beams. This experiment is a generalization of the Hong-Ou-Mandel interference effect for continuous variables, and constitutes a milestone towards continuous-variable entanglement of bright, ultrastable nondegenerate beams.

•Sep 30, 2003•1 citation

Quantum interference of twin optical beams, a typical example of correlated boson fields, is of great interest from the viewpoint of both fundamental and applied physics. Intensity correlated optical beams and their quantum interference bring the possibility of performing sub-shot-noise interferometry experiments which yield high-sensitivity in practical applications. A type-II doubly resonant optical parametric oscillator (OPO) has been built for research in quantum optics, to provide a source of ultrastable quantum correlated (twin) optical beams with continuously tunable frequency difference from zero up to several THz. Three servo loops have been built to control the frequency difference of the twin optical beams and sub-hertz stability has been achieved for frequency difference up to 100MHz. In particular, frequency degenerate twin beams are indistinguishable macroscopic quantum systems. A series of experimental results has been produced with these OPO-generated ultrastable twin beams: the observation of the generalized Hong-Ou-Mandel interference of untrastable twin optical beams, sub-shot-noise homodyne interferometry, and sub-shot-noise heterodyne polarimetry. Note: Abstract extracted from PDF text

We investigate experimentally the number and phase quantum noises of the light emitted by an ultrastable nondegenerate optical parametric oscillator (OPO) above threshold. Strong intensity correlations at the photon level -- number-difference squeezing or twin beams -- have already been observed by several groups. We have recently observed the twin-beam interference of a classically phase-locked OPO and have shown that the phase-difference is antisqueezed, as expected from the number-phase Heisenberg (in)equality. In this paper we describe the realization of a stable classical measurement of the joint quadratures of an OPO, as part of our ongoing effort to generate ultrastable EPR light beams simultaneously squeezed in number difference and phase sum.

We report the first measurement of the quantum phase-difference noise of an ultrastable nondegenerate optical parametric oscillator that emits twin beams classically phase locked at exact frequency degeneracy. The measurement illustrates the property of a lossless balanced beam splitter to convert number-difference squeezing into phase-difference squeezing, and thus provides indirect evidence for Heisenberg-limited interferometry using twin beams. This experiment is a generalization of the Hong-Ou-Mandel interference effect for continuous variables and constitutes a milestone towards continuous-variable entanglement of bright, ultrastable nondegenerate beams.

In recent years, several experiments have established the optical parametric oscillator (OPO) as a practical source of highly correlated twin beams. These beams have an intensity difference noise substantially below the associated shot noise, for noise frequencies within the OPO cavity bandwidth. They present the additional feature of being laserlike and intense, making them convenient for experimental applications. Refinements on our OPO characteristics and photodiode efficiencies have yielded a reduction of the noise power in the intensity difference of 86% below the shot noise level.1 A first use of twin beams is the production of a single light beam having an intensity squeezed noise. This can be achieved by monitoring the intensity of one beam with a photodiode and using this information to control the intensity fluctuations of the second beam with an electrooptic modulator.2 Other applications to high sensitivity spectroscopic measurements such as linear and nonlinear absorption or dispersion can now be considered for practical use.

Nondegenerate optical parametric oscillators generate above-threshold signal and idler beams that have intensity fluctuations correlated at the quantum level (twin beams). We describe what is to our knowledge the first high-sensitivity spectroscopy experiment using twin beams emitted by a cw optical parametric oscillator: a very weak two-photon absorption signal, in the 10(-7) range, is recorded on the 4S(1/2)-5S(1/2) transition of atomic potassium with a noise background that is reduced by 1.9 dB with respect to the shot-noise limit of the light used in the experiment.

We report the first measurement of the quantum phase-difference noise of an ultrastable nondegenerate optical parametric oscillator that emits twin beams classically phase-locked at exact frequency degeneracy. The measurement illustrates the property of a lossless balanced beam-splitter to convert number-difference squeezing into phase-difference squeezing and, thus, provides indirect evidence for Heisenberg-limited interferometry using twin beams. This experiment is a generalization of the Hong-Ou-Mandel interference effect for continuous variables, and constitutes a milestone towards continuous-variable entanglement of bright, ultrastable nondegenerate beams.