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1.
Spatial and temporal properties of parametric fluorescence around degeneracy in a type I LBO crystal
F. Devaux E. Lantz 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(1):117-124
We present a theoretical and experimental study of the spatio-temporal properties of the spontaneous parametric emission generated
in a type I LBO crystal around degeneracy. The number of quasi-phase-matched modes is shown to be equal to the number of spatio-temporal
degrees of freedom of the image that can be parametrically amplified. From this number, we demonstrate the possibility of
predicting the total number of photons generated by parametric fluorescence. Correlation is observed between spatial intensity
fluctuations corresponding to pairs of signal-idler modes.
Received 18 February 1999 and Received in final form 9 June 1999 相似文献
2.
C. Wiele F. Haake K. Rzażewski 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,5(3):405-409
We solve the superradiant laser model in two limiting cases. First the stationary low-pumping regime is considered where a
first-order phase transition in the semiclassical solution occurs. This discontinuity is smeared out in the quantum regime.
Second, we solve the model in the non-stationary regime where we find a temporally periodic solution. For a certain parameter
range well-separated pulses may occur.
Received: 19 June 1998 / Accepted: 19 October 1998 相似文献
3.
A. Casado T. Marshall R. Risco-Delgado E. Santos 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,13(1):109-119
We continue the study of parametric down conversion within the framework of the Wigner representation, by using a Maxwellian
approach developed in a recent paper [A. Casado et al., Eur. Phys. J. D 11, 465 (2000)]. This gives a mechanism, inside the crystal, for the production of the down-converted radiation. We obtain the
electric field to second order in the coupling constant by using the Green's function method, and compare our treatment with
the standard Hamiltonian approach. The spectrum of the down-converted radiation is calculated as a function of the parameters
of the nonlinear crystal (in particular the length) and the radius of the pumping beam.
Received 15 May 2000 相似文献
4.
A. Casado A. Fernández-Rueda T. Marshall J. Martínez R. Risco-Delgado E. Santos 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(3):465-472
The theory of parametric down conversion within the framework of the Wigner representation has been treated recently in a
series of papers using the standard model Hamiltonian. Here we take a more fundamental point of view studying the mechanism,
inside the crystal, for the production of the signal and idler beams. We begin from the evolution equations for the quantum
field operators, pass to the Wigner function and solve the resulting (Maxwell) equations with the use of the Green's function
method. We derive the time dependence of the coincidence detection probability as a function of the parameters of the nonlinear
crystal (in particular the length) the radius of the pumping beam, and the bandwidth of the filters in front of the detectors.
Received 24 January 2000 and Received in final form 24 March 2000 相似文献
5.
C.M. Granzow A. Liebman G. Mahler 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,2(1):131-142
Continuous measurement models are conveniently based on master equations specified by the respective Hamiltonian and appropriate
environment operators. As demonstrated by stochastic unraveling, the latter specify the dynamical process rather than static
detection modes. We show that certain environment operators acting on a simple system may, in fact, require extended networks
for implementation: Their Hamilton parameters re-appear in the effective environment operators of the reduced model. The resulting
quantum trajectories typically involve competing paths, which may give rise to different fluctuation and noise properties
even when the corresponding ensemble behavior is practically the same.
Received: 21 July 1997 / Received in final form: 10 November 1997 / Accepted: 27 October 1997 相似文献
6.
F.E. van Dorsselaer G. Nienhuis 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,2(2):175-180
We present a scheme for stochastic quantum-state diffusion (QSD) with adaptive noise to calculate the time evolution of an
arbitrary observable of an open system. The method is based on the fact that the observable is much less sensitive to adaptive
noise than to noise with a random phase. Hence, the individual realisations of the expectation value of the observable stay
closer to the average evolution and fewer realisations are required to obtain the ensemble average. This is illustrated by
applying QSD to a driven two-level system using both randomly phased and adaptive noise. Applying QSD with adaptive noise
to an undriven two-level system enables us to derive a deterministic Schr?dinger equation that produces the exact evolution
of an arbitrary observable.
Received: 31 July 1997 / Received in final form: 12 February 1998 / Accepted: 13 March 1998 相似文献
7.
M. Gangl H. Ritsch 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(1):29-40
We develop quantum models for the combined external and internal motion of atoms in a strongly coupled driven cavity mode
including the transverse degrees of freedom. Using a simplified Gaussian mode function we determine the parameter regimes
and prospects of 3D cooling and confinement of one or two atoms in the cavity field. Analysing the field dynamics for slow
atoms traversing the cavity, we show that the spectrum of the transmitted and spontaneously scattered light contains ample
information on the motional dynamics of the atom and can be nicely used to investigate the cooling properties of the system.
Including several atoms in the dynamics we show how motional correlations build up by the common interaction with the cavity
field. This can be looked upon as collisions at far distance and can be monitored via the transmitted field dynamics.
Received 5 March 1999 and Received in final form 4 May 1999 相似文献
8.
A. Lambrecht S. Reynaud 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(3):309-318
We study the influence of finite conductivity of metals on the Casimir effect. We put the emphasis on explicit theoretical
evaluations which can help comparing experimental results with theory. The reduction of the Casimir force is evaluated for
plane metallic plates. The reduction of the Casimir energy in the same configuration is also calculated. It can be used to
infer the reduction of the force in the plane-sphere geometry through the “proximity theorem”. Frequency dependent dielectric
response functions of the metals are represented either by the simple plasma model or, more accurately, by using the optical
data known for the metals used in recent experiments, that is Al, Au and Cu. In the two latter cases, the results obtained
here differ significantly from those published recently.
Received 30 July 1999 相似文献
9.
A. Lambrecht M.T. Jaekel S. Reynaud 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,3(1):95-104
We calculate the photon emission of a high finesse cavity moving in vacuum. The cavity is treated as an open system. The field
initially in the vacuum state accumulates a dephasing depending on the mirrors motion when bouncing back and forth inside
the cavity. The dephasing is not linearized in our calculation, so that qualitatively new effects like pulse shaping in the
time domain and frequency up-conversion in the spectrum are found. Furthermore we predict the existence of a threshold above
which the system should show self-sustained oscillations.
Received: 10 December 1997 / Received in final form: 27 March 1998 / Accepted: 27 March 1998 相似文献
10.
T. Möller K. von Haeften T. Laarman R. von Pietrowski 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,7(1):5-9
We introduce a novel control method for a delayed dynamical system exhibiting high-dimensional chaos. The control is based
on a negative feedback loop with an adaptive filtering, consisting of a selective filter, centered at the frequency of the
orbit to be stabilized, with the addition of a time derivative correction. The validity of the method is also discussed in
the framework of a space-like representation adopted to study the analogies between delayed dynamical systems and spatially
extended systems.
Received: 12 April 1999 相似文献
11.
X.-M. Hu J.-S. Peng 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,5(2):291-299
On the basis of the nondegenerate quantum-beat laser model, we introduce a coherent field which drives the transition between the upper lasing level and an
auxiliary level. We demonstrate that such a four-level system can produce squeezed two-mode laser without and with inversion.
When the laser is operated well above threshold, the intensity fluctuation in the average mode is reduced below the shot noise
with an optimum Mandel parameter Q=- 1/2. At the same time, the noises in the relative amplitude and the relative phase drop to their vaccum noise levels. Furthermore,
regardless of inversion, noninversion, and transition between inversion and noninversion, the optimum Mandel Q parameter of Q=- 1/2 is retained when the system operates well above threshold. A simple physical explanation of the squeezing mechanism
for two-mode squeezing is given.
Received: 22 December 1997 / Revised: 25 March 1998 / Accepted: 9 September 1998 相似文献
12.
S. Yuan J.-Y. Gao 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(2):267-272
A new scheme of the influence of quantum interference on the spontaneous emission in a coherently driven three-level medium
is presented in this paper. The results are the same with that discussed by [S.-Y. Zhu, L.M. Narducci, M.O. Scully, Phys.
Rev. A 52, 4791 (1995)] under resonance conditions, but they are different when the driven field is detuned.
Received 8 September 1999 and Received in final form 13 January 2000 相似文献
13.
K. Mølmer 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,5(2):301-305
We discuss the possibility of preparing an atomic sample of atoms with minimum fluctuations in the difference between populations
of two levels. A first scheme involves absorption of twin beams of light, and it presents a variant of a recent proposal for
atomic spin squeezing within an excited state manifold [Kuzmich et al., Phys. Rev. Lett. 79, 4782 (1997)]. A second scheme involves atoms with two stable states, and we suggest that by use of quantum non-demolition
detection and feed-back optical pumping, we may ensure a perfect agreement between the number of atoms in these two states.
Received: 14 May 1998 / Revised: 10 August 1998 / Accepted: 8 October 1998 相似文献
14.
H.P. Breuer B. Kappler F. Petruccione 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,1(1):9-13
A fast simulation algorithm for the calculation of multitime correlation functions of open quantum systems is presented. It
is demonstrated that any stochastic process which “unravels” the quantum Master equation can be used for the calculation of
matrix elements of reduced Heisenberg picture operators, and thus for the calculation of multitime correlation functions,
by extending the stochastic process to a doubled Hilbert space. The numerical performance of the stochastic simulation algorithm
is investigated by means of a standard example.
Received: 30 May 1997 / Revised: 4 November 1997 / Accepted: 7 November 1997 相似文献
15.
G. Scarcelli Y. Zhou Y. Shih 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(1):167-173
We report on a delayed-choice quantum eraser experiment
based on a two-photon imaging scheme using entangled photon pairs.
After the detection of a photon which passed through a
double-slit, a random delayed choice is made to erase or not erase
the which-path information by the measurement of its distant
entangled twin; the particle-like and wave-like behavior of the
photon are then recorded simultaneously and respectively by only
one set of joint detection devices. The present eraser takes
advantage of two-photon imaging. The complete which-path
information of a photon is transferred to its distant entangled
twin through a “ghost" image. The choice is made on the Fourier
transform plane of the ghost image between reading “complete
information" or “partial information" of the double-path. 相似文献
16.
We show that the conditional displacement operator acting upon arbitrary states of traveling waves can be well approximated by the action of a Kerr-medium placed between two beam splitters whose respective second ports are fed by highly excited coherent states. The scheme is deterministic, since it does not employ any detection event. Applications for generation of nonclassical states and measurement of Wigner function of arbitrary states are also considered. 相似文献
17.
F. Grassia J. -M. Courty S. Reynaud P. Touboul 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(1):101-110
We present a quantum network approach to real high sensitivity measurements. Thermal and quantum fluctuations due to active
as well as passive elements are taken into account. The method is applied to the analysis of the capacitive accelerometer
using the cold damping technique, developed for fundamental physics in space by ONERA and the ultimate limits of this instrument
are discussed. It is confirmed in this quantum analysis that the cold damping technique allows one to control efficiently
the test mass motion without degrading the noise level.
Received 20 April 1999 and Received in final form 2 July 1999 相似文献
18.
T. Golubeva Yu. Golubev C. Fabre N. Treps 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(1):179-193
In this paper, we investigate several properties of the
full signal-idler-pump mode quantum state generated by a triply
resonant non-degenerate Optical Parametric Oscillator operating
above threshold, with an injected wave on the signal and idler
modes in order to lock the phase diffusion process. We determine
and discuss the spectral purity of this state, which turns out not
to be always equal to 1 even though the three interacting modes
have been taken into account at the quantum level. We have seen
that the purity is essentially dependent on the weak
intensity of the injected light and on an asymmetry of the
synchronization. We then derive the expression of its total
three-mode Glauber P-function, and calculate the joint
signal-idler photon number probability distribution and
investigate their dependence on the injection. 相似文献
19.
Wang Kaige A. Sinatra L.A. Lugiato 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,12(2):339-349
We present a simple method, based on the quantum regression theorem, to calculate the quantum correlation spectra for two
optical beams in the linearized fluctuation regime. As an application, we discuss the dynamical instability, the squeezing
spectra and the QND properties of a crossed Kerr-type dispersive model.
Received 30 August 1999 and Received in final form 4 July 2000 相似文献
20.
In this paper, we investigate tunable control of the group velocity of a weak probe field propagating through an f-deformed Bose-Einstein condensate of Λ-type three-level atoms beyond the rotating wave approximation. For this purpose, we use an f-deformed generalization of an effective two-level quantum model of the three-level Λ-configuration without the rotating wave approximation in which the Gardiner’s phonon operators for Bose-Einstein condensate are deformed by an operator-valued function, , of the particle-number operator . We consider the collisions between the atoms as a special kind of f-deformation where the collision rate κ is regarded as the deformation parameter. We demonstrate the enhanced effect of subluminal and superluminal propagation based on electromagnetically induced transparency and electromagnetically induced absorption, respectively. In particular, we find that (i) the absorptive and dispersive properties of the deformed condensate can be controlled effectively in the absence of the rotating wave approximation by changing the deformation parameter κ, the total number of atoms and the counter-rotating terms parameter λ, (ii) by increasing the values of λ, κ and η = 1/N, the group velocity of the probe pulse changes, from subluminal to superluminal and (iii) beyond the rotating wave approximation, the subluminal and superluminal behaviors of the probe field are enhanced. 相似文献