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231.
I. Gatare J. Buesa H. Thienpont K. Panajotov M. Sciamanna 《Optical and Quantum Electronics》2006,38(4-6):429-443
Bistability as well as dynamics associated to polarization switching in a vertical-cavity surface-emitting laser (VCSEL) submitted
to orthogonal optical injection from an external master laser are investigated. Intensity-polarization switching bistability
is studied by increasing and decreasing the intensity of the injected beam and for a fixed frequency detuning, i.e. the frequency
offset between master and the free running VCSEL. Depending on the frequency detuning, bistable switching is experimentally
found to occur with or without injection locking of the fundamental mode to the master laser frequency. For large positive
detuning, injection locking of the first-order transverse mode with a strong depression of the fundamental mode has been observed.
The case of frequency – polarization switching bistability, i.e. when the frequency detuning is first decreased and then increased
for a fixed injected power, has also been theoretically analyzed. Qualitative comparison with previous experimental work is
presented for the dependence of the width of the bistable switching region on the injection strength level. Finally we show
an experimental result of complicated dynamics including period doubling route to chaos that accompany polarization switching
and which motivates future theoretical investigations. 相似文献
232.
The first-order-like phase transition (FOLT) in the dispersive optical bistability is investigated when the fluctuation in the incident light field is considered as colored noise. A unified colored-noise approximation is applied to obtain the steady state distribution (SSD) when either the intensity or phase fluctuations of the incident field are included in the system. For intensity fluctuations only, the curve of SSD is changed from single extreme to two extremes, and then to three extremes. The colored nature of the noise can reduce the fluctuation in the system. However, for phase fluctuations only, the FOLT is mainly induced by the colored nature of the noise. The curve of SSD is changed from single extreme to three extremes directly. There is no FOLT existing for white noise. 相似文献
233.
For 25 years the two metastable electronic states (SI and SII), accessible in the nitroprusside anion [Fe(CN)5NO]2− (NP) by irradiation with blue polarized light, have been the subject of intense investigations from several research groups.
This review article summarizes the most important experimental results in the field of photochromatic effects investigated
by nuclear resonant methods. The experimentally determined data have been compared with the results derived from density functional
theory calculations. The majority of results convincingly indicates: (i) the SI state is represented by the isonitrosyl conformation
(Fe-O-N) of the (NO+)-group and (ii) the SII state is represented by a dynamic conformation, in which a bending vibration of Fe-O-N as well as
a rotation of the (NO+)-group around the main molecular axis simultaneously occur. A possible formation of a new third metastable state observed
in rare-earth nitroprussides, which is stable at room temperature, will be discussed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
234.
P. Mathey M. Grapinet H. R. Jauslin B. Sturman D. Rytz S. Odoulov 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,39(3):445-451
A general analysis of the threshold behavior for the
photorefractive semi-linear oscillator is performed within the
linear approximation on the basis of the classical wave-coupling
model. This analysis shows that the well known particular results
on the frequency degenerate oscillation are valid only within a
restricted range of the external parameters. The theory specifies
the conditions for onset and properties of the frequency
non-degenerate oscillations, including the necessary values of the
coupling strength, pump intensity ratio, the increments of the
instability, and the frequency splits. Important generalizations
of the basic model are considered. 相似文献
235.
寻求具有卓越性能而又易于制造的纳米开关是纳米科技界的一个研究热点. 首先基于碳纳米管的结构双稳性提出了一种纳米开关的原型设计, 其由关到开的转换可通过径向压缩实现;
然后利用基于REBO-II作用势的分子动力学模拟, 系统分析了径向压缩单壁碳纳米管的力学行为和不同纳米管的双稳性特征, 给出了一些纳米管双稳性的特征参数, 对于工程设计具有一定的指导意义. 相似文献
236.
We investigate the nonlinear optical phenomena of the optical bistability and multistability via spontaneously generated coherence in an asymmetric double quantum well structure coupled by a weak probe field and a controlling field. It is shown that the threshold and hysteresis cycle of the optical bistability can be conveniently controlled only by adjusting the intensity of the SGC or the controlling field. Moreover, switching between optical bistability and multistability can be achieved. These studies may have practical significance for the preparation of optical bistable switching device. 相似文献
237.
Fano resonance and wave transmission through a chain structure with an isolated ring composed of defects
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We consider a discrete model that describes a linear chain of particles coupled to an isolated ring composed of N defects.This simple system can be regarded as a generalization of the familiar Fano-Anderson model.It can be used to model discrete networks of coupled defect modes in photonic crystals and simple waveguide arrays in two-dimensional lattices.The analytical result of the transmission coefficient is obtained,along with the conditions for perfect reflections and transmissions due to either destructive or constructive interferences.Using a simple example,we further investigate the relationship between the resonant frequencies and the number of defects N,and study how to affect the numbers of perfect reflections and transmissions.In addition,we demonstrate how these resonance transmissions and refections can be tuned by one nonlinear defect of the network that possesses a nonlinear Kerr-like response. 相似文献
238.
239.
在狭缝金属波导内放入非线性介质,利用非线性Kerr效应以及金属-非线性介质-金属所构成表面等离子体激元Fabry-Perot微腔形成的正反馈机制,在纳米尺度光子器件内实现光学双稳态。时域有限差分计算结果表明,由于表面等离子激元的局域增强效应,双稳态可以在低入射光强条件下发生。 相似文献
240.