共查询到20条相似文献,搜索用时 15 毫秒
1.
Lifu Zhang Xiquan Fu Jianqin Deng Shuangchun Wen Dianyan Fan 《Optics Communications》2011,284(8):2210-2214
We experimentally investigate the evolution of spatial modulation of broadband laser pulses with different pulse durations through a medium with non-instantaneous Kerr nonlinearity. By modifying the input laser pulse width, we observe the nonlinear growth of the spatial stripes that arise from interference with different modulation frequencies, and then obtain the gain spectra of the spatial modulation which clearly reveal the influence of relaxation effect on spatiotemporal modulation instability. We find that all gain spectra have the similar fastest growing frequency, but they have tails at higher frequency region in which the growth rate of gain is bigger for shorter pulse duration. The experimental results are confirmed by the perturbational analysis. 相似文献
2.
The Kerr nonlinearity of a left-handed material is analyzed in a four-level atomic system.It is shown that,due to the effect of quantum interference,a large enhanced Kerr nonlinearity accompanied by vanishing absorption can be realized via choosing appropriate parameters in this negative refraction atomic medium.It not only shows the large nonlinearity but also acts as the phase and amplitude compensating effects. 相似文献
3.
N. B. Gubar 《Journal of Applied Spectroscopy》1997,64(6):863-865
In the present article the effect of compression of Gaussian pulses during their opposing propagation in a medium with inertial
cubic nonlinearity is considered. Using methods of computer simulation, conditions are found that determine the optimum regime
of compression. It is shown that after single passage through the medium the compression degree is equal to two.
B. I. Stepanov Institute of Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 6, pp. 840–842, November–December, 1997. 相似文献
4.
XIE SuXia LI HongJian XU HaiQing ZHOU Xin FU ShaoLi & WU JinJun College of Physics Science Technology Central South University Changsha China College of Materials Science Engineering 《中国科学:物理学 力学 天文学(英文版)》2010,(3)
This paper has made a theoretical study of enhanced transmission through a gold grating with arrays of subwavelength slits filled with nonlinear Kerr medium. The results of the research are based on rigorous finite-difference time domain calculations. The resonance transmission peaks in the investigated wavelength range are produced as a result of the surface plasmon resonance collaborated with the localized waveguide resonance. The paper also gives a detailed analysis of the influence exerted by various fa... 相似文献
5.
研究了存在Kerr介质时,耦合双原子与单模压缩真空场双光子跃迁相互作用系统光场的量子特性,讨论了Kerr介质和原子间偶极-偶极相互作用对光场量子特性的影响. 结果表明:当Kerr效应和偶极-偶极相互作用可以忽略时,光场U2分量的涨落能被周期性地压缩,随着Kerr效应和偶极-偶极相互作用的增强,光场的压缩逐渐变浅,压缩次数减少;Kerr效应和偶极-偶极相互作用的影响使光场的二阶相干度时间演化曲线呈现周期性的崩塌-回复现象,但不论耦合强度如何,光子总是呈现聚束效应.
关键词:
Kerr介质
压缩真空场
耦合双原子
光场的量子特性 相似文献
6.
Nonreciprocal microwave devices, in which the transmission of waves is non-symmetric between two ports, are indispensable for the manipulation of information processing and communication. In this work, we show the nonreciprocal microwave transmission in a cavity magnonic system under the joint mechanism of phase modulation and magnon Kerr nonlinearity effect. In contrast to the schemes based on the standard phase modulation or magnon Kerr nonlinearity, we find that the joint mechanism enables the nonreciprocal transmission even at low power and makes us obtain a high nonreciprocal isolation ratio. Moreover, when two microwave modes are coupled to the magnon mode via a different coupling strength, the presented strong nonreciprocal response occurs, and it makes the nonreciprocal transmission manipulating by the magnetic field within a large adjustable range possible, which overcomes narrow operating bandwidths. This study may provide promising opportunities to realize nonreciprocal structures for wave transmission. 相似文献
7.
We have established the master equation for the micromaser with a Kerr medium,we have studied the photon statics of the micromaser with a Kerr medium field and analysed the influence of the Kerr effect on the photon statistics,The influence of the Kerr effect on the photon statistics is different in two regimes,In the thermal-atom regime,the Kerr effect produces quantum noise,and decreases the mean photon number.In the ultracold-atom regime,with the increase of the nonlinear parameter of the Kerr medium,the stability of the mean photon number and the normalized variance enhances the mean photon number,and the normalized variance exhibits collapse-revival phenomena periodically,their resonance peaks become lower,and the photon statistics of more and more regions are sub-Poissonian. 相似文献
8.
Lifu Zhang Shuangchun Wen Xiquan Fu Jianqin Deng Jin Zhang Dianyuan Fan 《Optics Communications》2010,283(10):2251-2214
We investigated the spatiotemporal modulation instability (MI) in a medium with a non-instantaneous Kerr response in which the nonlinear contribution to the refractive index is governed by a relaxing Debye type equation. The expression for the MI gain spectrum in non-instantaneous Kerr medium is obtained, which clearly reveals the influence of the finite time of the nonlinear response (relaxation effect) on the spatiotemporal MI. It is shown that, due to the relaxation effect, the spatiotemporal MI can appear for the case of anomalous dispersion and defocusing nonlinearity, while it cannot appear in instantaneous Kerr medium for the same case, and a new MI gain spectrum appears, adding to the conventional MI gain spectrum similar to that in an instantaneous Ker medium. In addition, the bandwidth of MI gain spectrum is extended and the maximum MI gain is reduced with increasing of the relaxation time. Interestingly, spatiotemporal MI can appear for any spatial frequencies in non-instantaneous Kerr medium for any combination of dispersion and nonlinearity. We have performed an experiment of MI in carbon disulfide (CS2), a typical non-instantaneous Kerr medium, which shows quantitative agreement with the theoretical analyses. 相似文献
9.
The giant enhancement of Kerr nonlinearity in a four-level inverted-Y atomic system is investigated theoretically. Compared with that generated in a generic three-level system, the Kerr nonlinearity can be enhanced by several orders of magnitude with vanishing linear absorption. The physical mechanism leading to the giant enhancement of Kerr nonlinearity is also discussed. 相似文献
10.
11.
《Physics letters. A》2020,384(24):126451
In this paper, we explore transverse electric surface waves propagating along the crystal with jump change of Kerr nonlinearity in dependence on field amplitude. The dielectric permittivity in the proposed model of nonlinearity is characterized by abruptly changing unperturbed dielectric constant and Kerr nonlinearity coefficient from one value to another when field amplitude exceeds the threshold value of the switching field. This allows to find exact solutions of model equations in different cases of nonlinearity signs, and to obtain the dependence of wave characteristics, including total power flux, on effective refractive index in explicit form. Such solutions describe two new types of nonlinear surface waves with specific structure depending on electric field amplitude. We derive the conditions of surface domain formation. It is found that the largest percentage of radiation is concentrated within the domain. 相似文献
12.
An interesting effect of optical Kerr nonlinearity is reported from theoretical investigation on the fundamental and first higher mode cutoff frequencies in single-mode fibers doped with highly nonlinear materials like CdSxSe1−x with W-type dispersion-flattened profiles. It is observed that whereas the single-mode regime decreases absolutely for dispersion-shifted profiles due to reduction of the first higher order mode cutoff frequency as is evident from earlier studies, it increases for W-type profiles for such nonlinearity taking its effect on the nonzero fundamental mode cutoff frequency into consideration. Thus, one can go further down below the fundamental mode cutoff frequency while using W-fibers in single mode nonlinear fiber devices involving evanescent field coupling in the low V region. 相似文献
13.
Enhancement of Kerr nonlinearity with vanishing absorption in a tripod scheme 总被引:1,自引:0,他引:1 下载免费PDF全文
The giant enhancement of Kerr nonlinearity in a four-level tripod
type system is investigated theoretically. By tuning the value of
the Rabi frequency of the coherent control field, owing to the
double dark resonances, the giant-enhanced Kerr nonlinearity can be
achieved within the right transparency window. The influence of
Doppler broadening is also discussed. 相似文献
14.
A consistent quantum theory of self-action and cross-interaction of coherent light pulses in a cubically nonlinear medium is developed by using the momentum operator of the field, which takes into account the inertial nonlinearity. Specific features of generation of the quadrature-squeezed states of light pulses are considered. The spectrum of fluctuations of a quadrature below the shot-noise level is analyzed as a function of the relaxation time of nonlinearity and the magnitude of nonlinear phase additions, related to the self-action and cross-interaction. 相似文献
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17.
Fidelity of quantum information for V-type three-level atom interacting with a number state light field in Kerr medium 下载免费PDF全文
In this paper the evolution characteristics of the fidelity of quantum information for the V-type three-level atom interacting with number state light field in Kerr meddium are investigated. It shows that the periodicity of the evolutions of fidelity of quantum information is influenced by the Kerr coefficient, the photon number of the initial field and intensity of light. The evolutions of the fidelity of quantum information are modulated by the initial number state field. The Rabi oscillation frequency and the modulation frequency of fidelity for the field and the system vary with the value of the Kerr coefficient. The evolutions of fidelity of quantum information obviously show the quantum collapse and revival behaviours in the system of atom interacting with light field. 相似文献
18.
以表面磁光克尔原理为机理,测量薄膜材料的磁性参数,实验上求得了饱和状态下坡莫合金的克尔偏转角,并测出了其磁滞回线. 相似文献
19.
Electrooptical Kerr effect has been studied in binary solutions of a dipolar liquid (-picoline, β-picoline) in a non-dipolar solvent (benzene, p-xylene) and 1,4-dioxane in the full range of concentrations of the dipolar component (0 ≤ f2 ≤ 1). The experimental Kerr constant Ks of the solutions, refraction index ns, density ρs and the dielectric constant εs have been measured and used for the calculation of the molar Kerr constants KSM within the Onsager local field model. Analysis of changes in the molar Kerr constants as a function of the solute concentration by fits of theoretical functions to the experimental ones has permitted a determination of the parameters characterizing intermolecular interactions in binary solutions. 相似文献
20.
Nonlinear susceptibility of a quantum dot (QD) embedded in a two-sided cavity, is studied theoretically from a weak-coupling to a strong-coupling regime. In the relevance of a quantum logic gate, the corresponding nonlinear phase shifts (Kerr effect) are estimated for coherent wavepackets including one photon on average. In the weak-coupling regime, the phase shift enhances strongly as a function of a coupling constant between the cavity photon and QD, and eventually saturates in the strong-coupling regime. We also show transmission spectra to evaluate the efficiency of the phase shift. Although the efficiency decreases monotonically in the weak-coupling regime, it rises in the strong-coupling regime. 相似文献