共查询到20条相似文献,搜索用时 62 毫秒
1.
S. S. Hassan H. A. Batarfi R. Saunders R. K. Bullough 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(3):403-416
A time-independent theoretical and numerical analysis of an optical bistable model of two-level atoms in a ring cavity, driven
by a coherent field and in contact with a squeezed vacuum field is presented in the two cases of absorptive and dispersive
optical bistability (OB). In the former case, a suitable choice of the phase of the squeezed vacuum field reduces the threshold
for OB to occur compared with the normal vacuum case. In the latter case, regions of OB are identified as one or two disconnected
simple closed curves depending on the cooperation parameter [0pt] : is the maximum possible value of the critical value of C at fixed values of the squeezed vacuum field parameters. Phase switching effects between different (output) states of the
system is investigated in detail. In the absorptive case, one- or two-way optical switching is possible depending on [0pt]
. We also present results which demonstrate more complicated switching behaviour in the dispersive case.
Received 12 March 1999 and Received in final form 20 August 1999 相似文献
2.
M. Darwish 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(3):547-556
Theoretical investigations of dynamical behavior in optical
parametric oscillators (OPO) have generally assumed that the cavity
detunings of the interacting fields are controllable parameters.
However, OPOs are known to experience mode hops, where the system
jumps to the mode of lowest cavity detuning. We note that this
phenomenon significantly limits the range of accessible detunings
and thus may prevent instabilities predicted to occur above a
minimum detuning from being evidenced experimentally. As a simple
example among a number of instability mechanisms possibly affected
by this limitation, we discuss the Hopf bifurcation leading to
periodic behavior in the monomode mean-field model of a triply
resonant OPO and show that it probably can be observed only in very
specific setups. 相似文献
3.
M.L. Ramón R. Meucci M. Ciofini A. Labate L. Calero 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(1):137-141
The formation and stabilization of spatio-temporal patterns in an annular CO2 laser is studied. We give experimental and numerical evidence of the role of a small spatial perturbation (consisting of
a thin metallic wire inserted in the optical cavity) in the selection and stabilization of patterns.
Received 15 December 1999 相似文献
4.
Z. C. Luo W. C. Xu C. X. Song A. P. Luo W. C. Chen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(3):693-697
Modulation instability with subsideband generation induced by periodic power variation in soliton fiber ring lasers is reported.
We found that different wavelength shifts of subsideband generation are related to different periodic power variation. The
period of power variation and wavelength shifts of subsideband can be changed by altering the linear cavity phase delay. It
is also found that the periodic power variation is caused by the interaction between the nonuniform polarization state of
the circulating light and the polarizer in the laser cavity. 相似文献
5.
L. Spinelli M. Brambilla 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,6(4):523-532
Cavity solitons were recently predicted in semiconductor microresonators grown with a vertical geometry. By exploiting a previously
introduced model valid for both passive and active configurations of a multiple-quantum-well device, we studied the response
in the time domain offered by such self-organized structures in the device, when a small modulated optical signal is applied.
Using appropriate symmetry considerations, the (2+1)-dimensional problem is reduced to a tractable form, by means of a semianalytical
method. We demonstrated that large differential-gain factors, competitive with those of other all-optical and some opto-electronic
devices, are attainable, when the output signal is collected at the peak of the cavity soliton. This fact, in connection with
the reconfigurability properties already established for cavity soliton arrays, allows to conceive different schemes for optical
information handling: feasible arrangements for parallel amplification and for signal commutation are proposed.
Received: 11 December 1998 / Received in final form: 25 February
1999 相似文献
6.
本文采用非线性法布里-珀罗腔的全光光学方法,在C_(60)/C_(70)薄膜中首次观测到双稳开关现象,其开关时间为10ns. 相似文献
7.
We demonstrate the switching on and off of spatial solitons in a semiconductor microresonator by injection of light coherent
with the background illumination. The results give evidence that the formation of the solitons and their switching are not
limited by thermal processes.
Received: 11 February 2002 / Revised version: 25 April 2002 / Published online: 8 August 2002 相似文献
8.
A. Pai S. V. Dhurandhar P. Hello J. -Y. Vinet 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(3):333-346
The large scale interferometric gravitational wave detectors consist of Fabry-Perot cavities operating at very high powers
ranging from tens of kW to MW for next generations. The high powers may result in several nonlinear effects which would affect
the performance of the detector. In this paper, we investigate the effects of radiation pressure, which tend to displace the
mirrors from their resonant position resulting in the detuning of the cavity. We observe a remarkable effect, namely, that
the freely hanging mirrors gain energy continuously and swing with increasing amplitude. It is found that the “time delay”,
that is, the time taken for the field to adjust to its instantaneous equilibrium value, when the mirrors are in motion, is
responsible for this effect. This effect is likely to be important in the optimal operation of the full-scale interferometers
such as VIRGO and LIGO.
Received 12 July 1999 相似文献
9.
G. Labeyrie G. L. Gattobigio T. Chanelière G. L. Lippi T. Ackemann R. Kaiser 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(2):337-348
We present an experimental study of nonlinear lensing of
near-resonant light by a cloud of laser-cooled rubidium atoms,
specifically aimed at understanding the role of the interaction
time between the light and the atomic vapor. We identify four
different nonlinear mechanisms, each associated with a different
time constant: electronic nonlinearity, Zeeman optical pumping,
hyperfine optical pumping and radiation pressure. Our observations
can be quite accurately reproduced using a simple rate equation
model which allows for a straightforward discussion of the various
effects. The results are important for planning
more refined experiments on transverse nonlinear optics and
self-organization in samples of cold atoms. 相似文献
10.
I. Rabbiosi A.J. Scroggie G.-L. Oppo 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(3):453-459
Quantum fluctuations of the signal field are shown to induce packed arrays of cavity solitons in a degenerate optical parametric
oscillator above threshold in the limit of large pump finesse relative to the signal finesse. The cavity solitons in the array
are formed by locked domain walls, and lead to a highly correlated quantum structure. The effect of the quantum fluctuations
is non-trivial since the arrays of cavity solitons have a far less stable than other stable solutions and disappear with decreasing
pump finesse. The transition from disorder to order due to quantum noise is also discussed.
Received 20 September 2002 / Received in final form 28 November 2002 Published online 11 February 2003 相似文献
11.
Engineering entanglement of a general three-level system interacting with a correlated two-mode nonlinear coherent state 总被引:2,自引:0,他引:2
Mahmoud Abdel-Aty Abdel-Shafy F. Obada 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(1):155-165
In this article a treatment of a three-level atom interacting with two modes of light in a cavity with arbitrary forms of
nonlinearities of both the fields and the intensity-dependent atom-field coupling is presented. A factorization of the initial
density operator is assumed, with the privileged field modes being in a pair-coherent state. We derive and illustrate an exact
expression for the time evolution of the density operator, by means of which we identify and numerically demonstrate the region
of parameters where significantly large entanglement can be obtained. We show that entanglement can be significantly influenced
by different kinds of nonlinearities. The nonlinear medium yields the superstructure of atomic Rabi oscillation. We propose
a generation of Bell-type states having a simple initial state preparation of the present system.
Received 29 July 2002 / Received in final form 18 October 2002 Published online 21 January 2003
RID="a"
ID="a"e-mail: abdelaty@uni-flensburg.dePresent address: Institut für Mathematik, Universit?t Flensburg, Germany. 相似文献
12.
M.L. Ramón R. Meucci E. Allaria S. Boccaletti 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,12(2):329-337
Competition among modes in an annular CO2 laser has been experimentally and numerically analyzed. During the coexistence of different patterns, each of them resulting
from the interaction of two transverse modes with opposite angular momentum, chaos has been experimentally detected. A numerical
model, derived from the Maxwell-Bloch equations and including symmetry breaking terms, enables the interpretation of the main
experimental features.
Received 10 March 2000 相似文献
13.
J. H. Li X. X. Yang 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,53(4):449-454
We analyze hybrid absorptive-dispersive optical bistability (OB)
behavior via tunable Fano-type interference based on intersubband
transitions in asymmetric double quantum wells (QWs) driven
coherently by a probe laser field by means of a unidirectional
ring cavity. We show that OB can be controlled efficiently by
tuning the energy splitting of the two excited states (the
coupling strength of the tunnelling), the Fano-type interference,
and the frequency detuning. The influence of the electronic
cooperation parameter on the OB behavior is also discussed. This
investigation may be used for optimizing and controlling the
optical switching process in the QW solid-state system, which is
much more practical than that in atomic system because of its
flexible design and the controllable interference strength. 相似文献
14.
Mudassar Aqueel Ahmad 《Optics Communications》2008,281(6):1635-1646
In this paper, we study the quantum phase properties of the field in a two-photon micromaser, including the effects of the finite detuning of the intermediate level. For initial coherent state of the cavity field and atoms initially in their excited state multipeak phase structure appears which eventually leads to the randomization of the cavity field phase. However, the approach towards the randomization depends upon the detuning. If the atoms are injected in a coherent superposition of their upper and lower atomic states then the phase distribution evolves into two-peak structure. For initial thermal state and atoms in polarized state, cavity field acquires some phase. We also consider the effect of finite Q of the cavity, random injection of the atoms and fluctuations in the interaction time. 相似文献
15.
The emission characteristics of a vertical-cavity surface-emitting laser (VCSEL) operated in a single-transverse mode and coupled to an external cavity with a diffraction grating as a frequency-selective element are analyzed experimentally, numerically and analytically. The experiments yield a rather abrupt turn-on of the VCSEL to a high-amplitude emission state and hysteresis phenomena. The experimental results are explained by numerical simulations and analytical calculations demonstrating the possibility of bistability between lasing and non-lasing states close to threshold. Hence, the scheme might be useful in all-optical photonic switching applications. A detailed bifurcation analysis near threshold is given by superimposing the numerical results with analytical steady-state curves. The mode selection and switching behavior obtained in the simulations can be interpreted from the point of view of the preference of states with the minimal total losses. 相似文献
16.
F. T. Arecchi R. Meucci 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(1):93-100
We report Stochastic Resonance and Coherence Resonance phenomena in
experiments using CO2 lasers. First, we consider a polarized laser with
feedback; for suitable feedback parameters, the laser intensity undergoes
homoclinic chaos consisting in the return to a saddle focus, where noise
controls the permanence time around the saddle. Second, we discuss a
quasi-isotropic laser where noise induces switching between two intensity
components with mutually orthogonal polarization. 相似文献
17.
We study the behavior of optical bistability (OB) in a triple semiconductor quantum well structure with tunnelling-induced interference, where the system is driven coherently by the probe laser inside the unidirectional ring cavity. The results show that we are able to control efficiently the bistable threshold intensity and the hysteresis loop by tuning the parameters of the system such as laser frequency and tunnelling-induced frequency splitting. This investigation can be used for the development of new types of nanoelectronic devices for realizing switching process. 相似文献
18.
19.
The pulse shape of a passively Q-switched microchip laser 总被引:2,自引:0,他引:2
T. Erneux P. Peterson A. Gavrielides 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,10(3):423-431
The shape of the intensity pulse of a passively Q-switched microchip laser is investigated numerically and analytically. Our
analysis is motivated by independent microchip laser experiments exhibiting nearly symmetric pulses in the case of a semiconductor
saturable absorber and asymmetric pulses in the case of a solid state saturable absorber. Asymptotic methods are used to determine
limiting behaviors of the pulse shape for both symmetric and asymmetric pulses. In the first case, we determine a sech2 solution parametrized by one parameter which can be determined by solving two coupled nonlinear algebraic equations. In the
second case, the pulse solution is decomposed into two distinct approximations exhibiting different amplitude and time scales
properties. We review earlier approximations of the repetition rate and the pulse width.
Received 2 August 1999 相似文献