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

Physical Review Letters

Squeezed-light – enhanced polarization interferometer

Philippe Grangier, Richard E. Slusher, Bernard Yurke, Arthur LaPorta

Published Nov 9, 1987• 495 citations
Publisher

Abstract

Enhancement of the sensitivity of a polarization interferometer beyond the limit set by vacuum fluctuations of the electromagnetic field has been obtained with use of squeezed light generated by a ${\mathrm{KTiOPO}}_{4}$ optical parametric amplifier. The increase in signal-to-noise ratio relative to the shot-noise limit is 2 dB. The corresponding improvement in the response time of the interferometer is measured to be a factor of 1.6.

DOI
10.1103/physrevlett.59.2153

Related papers

Precision measurement beyond the shot-noise limit

Min Xiao, Ling-An Wu, Harry J. Kimble

An improvement in precision beyond the limit set by the vacuum-state or zero-point fluctuations of the electromagnetic field is reported for the measurement of phase modulation in an optical interferometer. The experiment makes use of squeezed light to reduce the level of fluctuations below the shot-noise limit. An increase in the signal-to-noise ratio of 3.0 dB relative to the shot-noise limit is demonstrated, with the improvement currently limited by losses in propagation and detection and not by the degree of available squeezing.

Physical Review Letters•Jul 20, 1987•728 citations

Squeezed vacuum enhanced interferometry at the dark fringe

P. Granger, Richard E. Slusher, Arthur LaPorta

An experimental study of enhancement of interferometric sensitivity using squeezed vacuum fluctuations is described. By operating an interferometer at the dark fringe, large laser powers can be used for high sensitivity. It is possible to enhance the interferometric sensitivity beyond the shot-noise limit in the dark fringe arrangement by using an electrooptic modulator in the interferometer to vary the phase periodically away from the dark fringe. A detector at the dark output port can then operate at the shot-noise limit and detect phase imbalance at the sensitivity determined by power level at the bright output port.1 This shot-noise limit can be reduced further by illuminating the dark input port with squeezed vacuum, as demonstrated recently in balanced output port experiments.2,3 However, there are interesting limits to the sensitivity improvement expected in the dark fringe case.1 The experimental arrangement includes a polarization interferometer illuminated with 100 mW of 1.064-μm wavelength light from a Nd:YAG cw laser. Squeezed vacuum is generated by a KTP optical parametric amplifier. Experimental progress is reported at sensitivities in the nanoradian polarization rotation range.

Annual Meeting Optical Society of America•Jan 1, 1988•0 citations

Precision measurement beyond the shot-noise limit

Min Xiao, Ling-An Wu, H. J. Kimble

Improvements in precision beyond the limit set by the vacuum state or zero-point fluctuations of the field are reported for two optical experiments. Both experiments employ the squeezed light from an optical parametric oscillator to reduce the level of fluctuations in one of two quadrature phase amplitudes below the shot-noise level (SNL). The first experiment follows the work of Caves1 on precision interferometry with squeezed states. An increase in signal-to-noise of 2.5 dB relative to the SNL is demonstrated for the detection of phase modulation in a Mach-Zehnder interferometer. In the second experiment amplitude modulation is encoded on a weak signal beam with an acoustooptic modulator. For the case of a squeezed signal beam compared with a beam in a coherent state, an improvement in sensitivity of 2.5 dB is achieved for the detection of amplitude changes of the field. The observed increases in sensitivity in both experiments are currently limited by simple linear losses in propagation and detection and not by the degree of available squeezing.

Annual Meeting Optical Society of America•Jan 1, 1987•3 citations

Squeezed states of light

Harry J. Kimble

Squeezed states of the electromagnetic field are characterized by a reduction of fluctuations for one of two quadrature phase amplitudes below the level of fluctuations for the vacuum state. This reduction is a manifestly quantum or nonclassical feature which is of great interest in its own right but also potentially important for precision measurement with sensitivity beyond the shot-noise or vacuum-state limit. We describe three different experiments in which squeezed light has been generated in our laboratory involving parametric downconversion, intracavity frequency doubling, and optical bistability with two-state atoms. By employing the squeezed light produced by a subthreshold optical parametric oscillator, we have achieved improvements in sensitivity beyond the vacuum-state limit for the detection of both phase and amplitude changes of the electromagnetic field. An alternate route to sensitivity beyond the vacuum-state limit is through quantum nondemolition measurement, where we have suggested and are implementing a scheme involving parametric conversion and polarization mixing.

Annual Meeting Optical Society of America•Jan 1, 1988•0 citations

Kerr Squeezing in Optical Fibers for Sensitivity Enhancement of Interferometers

Nikolay A. Kalinin, Elena A. Anashkina, Gerd Leuchs +1 more

We developed a new simple all-fiber setup for generation of polarization-squeezed states. The setup reliably generates −5 ± 0.5 dB of squeezing which is stable for a long time without any adjustments. We applied this polarization squeezed light to a polarization interferometer and demonstrated an increase of the signal-to-noise ratio by 4 ± 0.5 dB.

International Conference Laser Optics (ICLO)•Jun 20, 2022•1 citation

Squeezing-enhanced simultaneous measurement of polarization angle and ellipticity beyond the shot noise limit

Peng Yang, Sheng Feng

An experimental scheme is proposed for squeezing-enhanced simultaneous measurement of the polarization angle and ellipticity of laser beam beyond the shot noise limit. In the scheme, a two-mode squeezed light is exploited to enhance the sensitivity of the measurement of polarization rotation angle, and a single-mode squeezed light is used to improve the sensitivity of ellipticity measurement. Noise analysis is performed to show that the signal-to-noise ratios in both the measurements of polarization angle and ellipticity can exceed the shot noise limit. This work is expected to be of considerable interest for experiments such as the observation of vacuum magnetic birefringence, gravitational wave detection, spin–orbital interaction, material characterization, polarization microscopy, atomic magnetometer, or biomedical optics.

Journal of the Optical Society of America B•Oct 27, 2025•1 citation
Enhancement of the sensitivity of a polarization interferometer beyond the limit set by vacuum fluctuations of the electromagnetic field has been obtained with use of squeezed light generated by a KTiOPO4{\mathrm{KTiOPO}}_{4}KTiOPO4​ optical parametric amplifier. The increase in signal-to-noise ratio relative to the shot-noise limit is 2 dB. The corresponding improvement in the response time of the interferometer is measured to be a factor of 1.6.
An improvement in precision beyond the limit set by the vacuum-state or zero-point fluctuations of the electromagnetic field is reported for the measurement of phase modulation in an optical interferometer. The experiment makes use of squeezed light to reduce the level of fluctuations below the shot-noise limit. An increase in the signal-to-noise ratio of 3.0 dB relative to the shot-noise limit is demonstrated, with the improvement currently limited by losses in propagation and detection and not by the degree of available squeezing.
An experimental study of enhancement of interferometric sensitivity using squeezed vacuum fluctuations is described. By operating an interferometer at the dark fringe, large laser powers can be used for high sensitivity. It is possible to enhance the interferometric sensitivity beyond the shot-noise limit in the dark fringe arrangement by using an electrooptic modulator in the interferometer to vary the phase periodically away from the dark fringe. A detector at the dark output port can then operate at the shot-noise limit and detect phase imbalance at the sensitivity determined by power level at the bright output port.1 This shot-noise limit can be reduced further by illuminating the dark input port with squeezed vacuum, as demonstrated recently in balanced output port experiments.2,3 However, there are interesting limits to the sensitivity improvement expected in the dark fringe case.1 The experimental arrangement includes a polarization interferometer illuminated with 100 mW of 1.064-μm wavelength light from a Nd:YAG cw laser. Squeezed vacuum is generated by a KTP optical parametric amplifier. Experimental progress is reported at sensitivities in the nanoradian polarization rotation range.
Improvements in precision beyond the limit set by the vacuum state or zero-point fluctuations of the field are reported for two optical experiments. Both experiments employ the squeezed light from an optical parametric oscillator to reduce the level of fluctuations in one of two quadrature phase amplitudes below the shot-noise level (SNL). The first experiment follows the work of Caves1 on precision interferometry with squeezed states. An increase in signal-to-noise of 2.5 dB relative to the SNL is demonstrated for the detection of phase modulation in a Mach-Zehnder interferometer. In the second experiment amplitude modulation is encoded on a weak signal beam with an acoustooptic modulator. For the case of a squeezed signal beam compared with a beam in a coherent state, an improvement in sensitivity of 2.5 dB is achieved for the detection of amplitude changes of the field. The observed increases in sensitivity in both experiments are currently limited by simple linear losses in propagation and detection and not by the degree of available squeezing.
Squeezed states of the electromagnetic field are characterized by a reduction of fluctuations for one of two quadrature phase amplitudes below the level of fluctuations for the vacuum state. This reduction is a manifestly quantum or nonclassical feature which is of great interest in its own right but also potentially important for precision measurement with sensitivity beyond the shot-noise or vacuum-state limit. We describe three different experiments in which squeezed light has been generated in our laboratory involving parametric downconversion, intracavity frequency doubling, and optical bistability with two-state atoms. By employing the squeezed light produced by a subthreshold optical parametric oscillator, we have achieved improvements in sensitivity beyond the vacuum-state limit for the detection of both phase and amplitude changes of the electromagnetic field. An alternate route to sensitivity beyond the vacuum-state limit is through quantum nondemolition measurement, where we have suggested and are implementing a scheme involving parametric conversion and polarization mixing.
An experimental scheme is proposed for squeezing-enhanced simultaneous measurement of the polarization angle and ellipticity of laser beam beyond the shot noise limit. In the scheme, a two-mode squeezed light is exploited to enhance the sensitivity of the measurement of polarization rotation angle, and a single-mode squeezed light is used to improve the sensitivity of ellipticity measurement. Noise analysis is performed to show that the signal-to-noise ratios in both the measurements of polarization angle and ellipticity can exceed the shot noise limit. This work is expected to be of considerable interest for experiments such as the observation of vacuum magnetic birefringence, gravitational wave detection, spin–orbital interaction, material characterization, polarization microscopy, atomic magnetometer, or biomedical optics.