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

Annual Meeting Optical Society of America

Parametric DFB resonator, squeezing, and Unruh radiation

H. A. Haus

Published Jan 1, 1989• 0 citations
Publisher

Abstract

An accelerated mirror generates photons from vacuum. This process is known as Unruh radiation.1 A uniform distribution of dielectric sheets spaced much less than a wavelength apart produces a net change in the effective index. When the sheets are displaced in a spatially periodic manner, a grating is formed. Motion of the sheets results in a time dependent (parametrically varying) grating that can produce squeezing. In this configuration, the squeezing is ascribed to Unruh radiation. A field analysis of moving dielectric sheets in the background of the zero-point fluctuation field is presented in this paper and shown to correspond to the Unruh formula. Recently, Yablonovitch proposed to use laser-generated exploding plasmas to simulate an accelerating mirror surface.2 We propose another simulation of accelerating mirrors with laser light that could lead to a laboratory experiment. If a grating is produced in a nonlinear fiber ring resonator, with one port of the 50/50 beam splitter fed by the pump, the other used as the signal port, the Unruh radiation emerges from the signal port and the pump is separated out automatically.

DOI
10.1364/oam.1989.wh3

Related papers

Moving mirrors and time-varying dielectrics

Harry Johnston, Sarben Sarkar

The spectral distribution of light generated by a finite cavity with one moving mirror is compared with that produced by a fixed cavity containing a time-varying dielectric. In both cases a motion over a finite time interval is considered. Although the moving mirror is usually considered to be an idealization for the time-varying dielectric, there are qualitative differences in the spectra produced. The spectral distribution for the moving mirror case behaves as 1/${\mathit{n}}^{3}$, while that for the time-varying dielectric behaves on average as 1/${\mathit{n}}^{4}$ but is rapidly oscillating.

Physical Review A•May 1, 1995•37 citations

Squeezed light generation in a monomode optical fiber

Mary J. Potasek, Bernard Yurke

Squeezed light, in which the quantum noise in one amplitude component is reduced below the vacuum level, has been generated using parametric processes. The starting point described here is the nonlinear Schrodinger equation which models light propagating through optical fibers. When such a dispersive nonlinear medium with a third-order susceptibility is pumped with an optical beam, squeezing can result. It is found that the degree of squeezing oscillates as a function of fiber length in the normal dispersion regime, whereas in the anomalous dispersion regime, it grows exponentially with fiber length. Examination of squeezing near the fiber’s zero dispersion wavelength shows that odd-order dispersive terms have no effect on squeezing. However, small values of higher-order even terms have significant effects on squeezing. In practice, high-frequency components of the squeezing spectrum are difficult to obtain. However, it is shown that a cross-correlation technique may be used to explore the frequency dependence of the squeezing spectrum.

Annual Meeting Optical Society of America•Jan 1, 1987•0 citations

Squeezed pulse vacuum from fiber-ring interferometer

K. Bergman, H. A. Haus

Squeezing with degenerate parametric amplification sacrifices the power needed for the pump.1 Squeezing by using the third- order nonlinearity does not necessarily sacrifice the pump power, because it remains at the same frequency as the squeezed radiation. Because the third-order nonlinearity is weak, long interaction lengths must be used, i.e., optical fibers. Past experiments with quasi excitation in optical fibers were plagued by stimulated Brillouin scattering (SBS) and guided acoustic wave acoustic Brillouin scattering (GAWBS).2 The use of pulses raises the peak power and the SBS threshold, allowing use of shorter fibers. A Mach-Zehnder interferometer configuration separates the pump from the squeezed vacuum.3 This has two advantages: the pump power can be reused as the local oscillator power, and the squeezed radiation can be measured closer to zero frequency (30 kHz) because the pump fluctuations are absent.

Annual Meeting Optical Society of America•Jan 1, 1990•0 citations

Quantum electrodynamics of accelerated atoms in free space and in cavities

Alexey A. Belyanin, Vitaly V. Kocharovsky, Federico Capasso +3 more

We consider a gedanken experiment with a beam of atoms in their ground state that are accelerated through a single-mode cavity. We show that taking into account of the ``counterrotating'' terms in the interaction Hamiltonian leads to the excitation of an atom with simultaneous emission of a photon into a field mode. In free space, when the atom-field interaction is turning on/off adiabatically, the only nonadiabatic effect that causes the excitation is the time-dependent Doppler shift. The resulting ratio of emission and absorption probabilities is exponentially small and is described by the Unruh factor. In the opposite case of rapid turn on of the interaction on the cavity boundaries the above ratio is much greater and radiation is produced with an intensity which can exceed the intensity of radiation in free space by many orders of magnitude. In both cases real photons are produced. The cavity field at steady state has a thermal density matrix. However, under some conditions laser gain is possible. We present a detailed discussion of how the acceleration of atoms affects the generated cavity field in different situations. We identify a common physical mechanism behind the Unruh effect and similar QED radiation processes.

arXiv:quant-ph/0412134•Physical Review A•Aug 15, 2006•59 citations

Room temperature generation of amplitude squeezed light from 1550 nm distributed feedback semiconductor laser

Francine Jérémie, C. Chabran, Philippe B. Gallion

The control of the quantum state of light has recently been studied extensively, aiming at the achievement of ultra-low noise below the shot noise limit. Several experiments showed that amplitude squeezing could be achieved in constant-current-driven semiconductor lasers. However, the generation of amplitude-squeezed light from distributed feedback semiconductor lasers (DFB) has been up to now considerably less successful than that from Fabry-Perot devices. Simulations indicate that DFB structures with high coupling coefficient length product kL are unlikely to be good sources of squeezed light, because of the evanescence of the optical fields along the grating [1]. They also show, that for low kL values the lowest achievable intensity noise depends on the structure of the laser diode and can be higher than expected from the laser quantum efficiency alone.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jan 1, 1998•0 citations

Generation of squeezing by polarizable media?

Roy J. Glauber, Maciej Lewenstein

Photons created in free space change in nature when interacting with even the simplest of linearly polarizable media. There is a sense in which this transformation characteristically involves the effects of squeezing as well as scattering. The field fluctuations present in the media or their vicinity may, as a result, differ dramatically from zero-point fluctuations in free space. Such altered fluctuation properties are observable, for example, through the inhibition or enhancement of the spontaneous emission rates of excited probe atoms. Not all the effects that have been discussed in connection with squeezing are observable, however. Because interactions with polarizable media can be described by means of mode expansions for which the photon occupation numbers are conserved, they do not lead to qualitative changes in the counting statistics of photoabsorption processes. The field of a dielectric illuminated by a coherent laser beam, for example, yields Poisson photon counting statistics everywhere. We shall discuss other experiments bearing on field fluctuations in dynamic models of polarizable media as well as passive ones.

Annual Meeting Optical Society of America•Jan 1, 1987•1 citation
An accelerated mirror generates photons from vacuum. This process is known as Unruh radiation.1 A uniform distribution of dielectric sheets spaced much less than a wavelength apart produces a net change in the effective index. When the sheets are displaced in a spatially periodic manner, a grating is formed. Motion of the sheets results in a time dependent (parametrically varying) grating that can produce squeezing. In this configuration, the squeezing is ascribed to Unruh radiation. A field analysis of moving dielectric sheets in the background of the zero-point fluctuation field is presented in this paper and shown to correspond to the Unruh formula. Recently, Yablonovitch proposed to use laser-generated exploding plasmas to simulate an accelerating mirror surface.2 We propose another simulation of accelerating mirrors with laser light that could lead to a laboratory experiment. If a grating is produced in a nonlinear fiber ring resonator, with one port of the 50/50 beam splitter fed by the pump, the other used as the signal port, the Unruh radiation emerges from the signal port and the pump is separated out automatically.
The spectral distribution of light generated by a finite cavity with one moving mirror is compared with that produced by a fixed cavity containing a time-varying dielectric. In both cases a motion over a finite time interval is considered. Although the moving mirror is usually considered to be an idealization for the time-varying dielectric, there are qualitative differences in the spectra produced. The spectral distribution for the moving mirror case behaves as 1/n3{\mathit{n}}^{3}n3, while that for the time-varying dielectric behaves on average as 1/n4{\mathit{n}}^{4}n4 but is rapidly oscillating.
Squeezed light, in which the quantum noise in one amplitude component is reduced below the vacuum level, has been generated using parametric processes. The starting point described here is the nonlinear Schrodinger equation which models light propagating through optical fibers. When such a dispersive nonlinear medium with a third-order susceptibility is pumped with an optical beam, squeezing can result. It is found that the degree of squeezing oscillates as a function of fiber length in the normal dispersion regime, whereas in the anomalous dispersion regime, it grows exponentially with fiber length. Examination of squeezing near the fiber’s zero dispersion wavelength shows that odd-order dispersive terms have no effect on squeezing. However, small values of higher-order even terms have significant effects on squeezing. In practice, high-frequency components of the squeezing spectrum are difficult to obtain. However, it is shown that a cross-correlation technique may be used to explore the frequency dependence of the squeezing spectrum.
Squeezing with degenerate parametric amplification sacrifices the power needed for the pump.1 Squeezing by using the third- order nonlinearity does not necessarily sacrifice the pump power, because it remains at the same frequency as the squeezed radiation. Because the third-order nonlinearity is weak, long interaction lengths must be used, i.e., optical fibers. Past experiments with quasi excitation in optical fibers were plagued by stimulated Brillouin scattering (SBS) and guided acoustic wave acoustic Brillouin scattering (GAWBS).2 The use of pulses raises the peak power and the SBS threshold, allowing use of shorter fibers. A Mach-Zehnder interferometer configuration separates the pump from the squeezed vacuum.3 This has two advantages: the pump power can be reused as the local oscillator power, and the squeezed radiation can be measured closer to zero frequency (30 kHz) because the pump fluctuations are absent.
We consider a gedanken experiment with a beam of atoms in their ground state that are accelerated through a single-mode cavity. We show that taking into account of the ``counterrotating'' terms in the interaction Hamiltonian leads to the excitation of an atom with simultaneous emission of a photon into a field mode. In free space, when the atom-field interaction is turning on/off adiabatically, the only nonadiabatic effect that causes the excitation is the time-dependent Doppler shift. The resulting ratio of emission and absorption probabilities is exponentially small and is described by the Unruh factor. In the opposite case of rapid turn on of the interaction on the cavity boundaries the above ratio is much greater and radiation is produced with an intensity which can exceed the intensity of radiation in free space by many orders of magnitude. In both cases real photons are produced. The cavity field at steady state has a thermal density matrix. However, under some conditions laser gain is possible. We present a detailed discussion of how the acceleration of atoms affects the generated cavity field in different situations. We identify a common physical mechanism behind the Unruh effect and similar QED radiation processes.
The control of the quantum state of light has recently been studied extensively, aiming at the achievement of ultra-low noise below the shot noise limit. Several experiments showed that amplitude squeezing could be achieved in constant-current-driven semiconductor lasers. However, the generation of amplitude-squeezed light from distributed feedback semiconductor lasers (DFB) has been up to now considerably less successful than that from Fabry-Perot devices. Simulations indicate that DFB structures with high coupling coefficient length product kL are unlikely to be good sources of squeezed light, because of the evanescence of the optical fields along the grating [1]. They also show, that for low kL values the lowest achievable intensity noise depends on the structure of the laser diode and can be higher than expected from the laser quantum efficiency alone.
Photons created in free space change in nature when interacting with even the simplest of linearly polarizable media. There is a sense in which this transformation characteristically involves the effects of squeezing as well as scattering. The field fluctuations present in the media or their vicinity may, as a result, differ dramatically from zero-point fluctuations in free space. Such altered fluctuation properties are observable, for example, through the inhibition or enhancement of the spontaneous emission rates of excited probe atoms. Not all the effects that have been discussed in connection with squeezing are observable, however. Because interactions with polarizable media can be described by means of mode expansions for which the photon occupation numbers are conserved, they do not lead to qualitative changes in the counting statistics of photoabsorption processes. The field of a dielectric illuminated by a coherent laser beam, for example, yields Poisson photon counting statistics everywhere. We shall discuss other experiments bearing on field fluctuations in dynamic models of polarizable media as well as passive ones.