A potential application of squeezed-state light is to improve the sensitivity of high-precision interferometers whose performance is generally limited by photon shot noise or photon-counting statistics. Such interferometers include passive laser gyroscopes and the very sensitive interferometers being developed to detect cosmic gravitational waves. One usually operates a high-precision interferometer in a differential mode, so that noise from the (laser) light source is in principle irrelevant. Operation in a differential mode means that there is a second, normally unused input port. Vacuum noise entering this second port is responsible for the irreducible photon shot noise at the interferometer’s output. Injecting squeezed-state light into the normally unused input port can improve the sensitivity. I discuss the use of squeezed-state light in ring interferometers, delayline Michelson interferometers, and Fabry-Perot interferometers. Included in the discussion are real degrading effects, such as losses, inefficient photodetectors, and laser noise in the presence of nonideal fringe contrast. I explore the compatibility of the squeezed-state technique with other exotic techniques for improving sensitivity, such as Drever's idea for power recycling. Sensitivity estimates for various configurations and techniques are presented.A potential application of squeezed-state light is to improve the sensitivity of high-precision interferometers whose performance is generally limited by photon shot noise or photon-counting statistics. Such interferometers include passive laser gyroscopes and the very sensitive interferometers being developed to detect cosmic gravitational waves. One usually operates a high-precision interferometer in a differential mode, so that noise from the (laser) light source is in principle irrelevant. Operation in a differential mode means that there is a second, normally unused input port. Vacuum noise entering this second port is responsible for the irreducible photon shot noise at the interferometer’s output. Injecting squeezed-state light into the normally unused input port can improve the sensitivity. I discuss the use of squeezed-state light in ring interferometers, delayline Michelson interferometers, and Fabry-Perot interferometers. Included in the discussion are real degrading effects, such as losses, inefficient photodetectors, and laser noise in the presence of nonideal fringe contrast. I explore the compatibility of the squeezed-state technique with other exotic techniques for improving sensitivity, such as Drever's idea for power recycling. Sensitivity estimates for various configurations and techniques are presented.

Annual Meeting Optical Society of AmericaJan 1, 19861 citation

Squeezed States in Phase-Sensing Interferometers

Roy S. Bondurant, Jeffrey H. Shapiro

Springer eBooksJan 1, 19849 citations

Experimental characterization of frequency-dependent squeezed light

S. Chelkowski, H. Vahlbruch, Boris Hage +4 more

We report on the demonstration of broadband squeezed laser beams that show a frequency-dependent orientation of the squeezing ellipse. Carrier frequency as well as quadrature angle were stably locked to a reference laser beam at $1064\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ . This frequency-dependent squeezing was characterized in terms of noise power spectra and contour plots of Wigner functions. The latter were measured by quantum state tomography. Our tomograph allowed a stable lock to a local oscillator beam for arbitrary quadrature angles with $\ifmmode\pm\else\textpm\fi{}1\ifmmode^\circ\else\textdegree\fi{}$ precision. Frequency-dependent orientations of the squeezing ellipse are necessary for squeezed states of light to provide a broadband sensitivity improvement in third-generation gravitational-wave interferometers. We consider the application of our system to long-baseline interferometers such as a future squeezed-light upgraded GEO 600 detector.We report on the demonstration of broadband squeezed laser beams that show a frequency-dependent orientation of the squeezing ellipse. Carrier frequency as well as quadrature angle were stably locked to a reference laser beam at $1064\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. This frequency-dependent squeezing was characterized in terms of noise power spectra and contour plots of Wigner functions. The latter were measured by quantum state tomography. Our tomograph allowed a stable lock to a local oscillator beam for arbitrary quadrature angles with $\ifmmode\pm\else\textpm\fi{}1\ifmmode^\circ\else\textdegree\fi{}$ precision. Frequency-dependent orientations of the squeezing ellipse are necessary for squeezed states of light to provide a broadband sensitivity improvement in third-generation gravitational-wave interferometers. We consider the application of our system to long-baseline interferometers such as a future squeezed-light upgraded GEO 600 detector.

arXiv:0706.4479Physical Review AJan 10, 2005102 citations

Measurement of the quantum states of squeezed light

Gerd Breitenbach, Stephan Schiller, J. Mlynek

NatureMay 1, 1997545 citations

10 dB interferometer enhancement by squeezing of photon shot noise with sub-femtometer resolution and eye-safe optical power

Jascha Zander, Christian Rembe, Roman Schnabel

Abstract Quantum technologies that exploit quantum-correlated resources offer advantages over quantum technologies that just exploit coherent states. Here we propose and demonstrate the exploitation of squeezed light to enhance laser interferometers being at the sensitivity limit of eye-safe optical powers into a new regime otherwise impossible without sacrificing eye-safety. We realised a homodyne Mach–Zehnder interferometer that in its arms used an eye-safe combined optical power of only 10 mW at the wavelength of 1550 nm, and nevertheless achieved a displacement noise spectral density of as low as 0.26 fm Hz−1/2. This value is more than a factor of 10 below what is possible with 10 mW in ideal coherent states at 1550 nm and slightly lower than what is possible with 100 mW at the same wavelength. We envision a new user application for squeezed light in avoiding costs for laser safety measures.Abstract Quantum technologies that exploit quantum-correlated resources offer advantages over quantum technologies that just exploit coherent states. Here we propose and demonstrate the exploitation of squeezed light to enhance laser interferometers being at the sensitivity limit of eye-safe optical powers into a new regime otherwise impossible without sacrificing eye-safety. We realised a homodyne Mach–Zehnder interferometer that in its arms used an eye-safe combined optical power of only 10 mW at the wavelength of 1550 nm, and nevertheless achieved a displacement noise spectral density of as low as 0.26 fm Hz−1/2. This value is more than a factor of 10 below what is possible with 10 mW in ideal coherent states at 1550 nm and slightly lower than what is possible with 100 mW at the same wavelength. We envision a new user application for squeezed light in avoiding costs for laser safety measures.

Quantum Science and TechnologyOct 17, 202215 citations

1064\phantom{\rule{0.3em}{0ex}}\mathrm{nm}

. This frequency-dependent squeezing was characterized in terms of noise power spectra and contour plots of Wigner functions. The latter were measured by quantum state tomography. Our tomograph allowed a stable lock to a local oscillator beam for arbitrary quadrature angles with $\ifmmode\pm\else\textpm\fi{}1\ifmmode^\circ\else\textdegree\fi{}$ precision. Frequency-dependent orientations of the squeezing ellipse are necessary for squeezed states of light to provide a broadband sensitivity improvement in third-generation gravitational-wave interferometers. We consider the application of our system to long-baseline interferometers such as a future squeezed-light upgraded GEO 600 detector.