共查询到20条相似文献,搜索用时 500 毫秒
1.
2.
一种双模叠加态光场的两种非线性高阶压缩效应 总被引:177,自引:63,他引:114
本文在发展现有理论的基础上提出了双模及多模辐射场的两种非线性高阶压缩(即N次方Y压缩和N次方H压缩)的定义,根据量子力学中的线性叠加原理构造了一美双模叠加志光场|ψ>,对|ψ>的N次方Y压缩及N次方H压缩效应进行了详细研究.结果表明:双模叠加态光场|ψ>是一种典型的非经典光场,它可具有任意阶的N次方Y压缩及N次方H压缩效应;并且,在一定的条件下,这两种非线性高阶压缩效应均可呈现出周期性变化的特性.文献7的单模辐射场振幅N次方压缩的定义,仅仅是本文所提出的N次方Y压缩和N次方H压缩这两种非线性高阶压缩的一般定义在k=1条件下的特例. 相似文献
3.
多模偶相干态光场中的N次方Y压缩与N次方H压缩特性研究 总被引:62,自引:39,他引:23
本文根据新近建立的多模辐射场的广义非线性等阶高阶压缩理论,对多模偶相干态光场冲|ψ,e〉q中的N次方Y压缩、N次方H压缩、N-Y最小测不准态以及N-H最小测不准态等进行了详细研究。结果表明:1)当N为偶数时,态|ψ,e〉q恒处于N-Y最小测不准态;当N为奇数时,态|ψ,e〉q在一定条件下存在着周期性变化的、任意阶的N次方Y压缩效应,2)当q·N为偶数时,态|ψ,e〉q恒处于N-H最小测不准态。当q·N为奇数时,在另外的条件下,态|ψ,e〉q存在着周期性变化的、任意阶的N次方H压缩效应。3)N次方Y压缩效应与N次方H压缩效应两者的压缩程度和深度均与几率幅yq(e)、压缩参数Rj、各模的初始相位ψj(或者初始相位和∑j=1qψj)、压缩阶数N及腔模总数q等非线性相关,后者与上述诸参量的非线性关联程度要比前者的更强。 相似文献
4.
第二类奇偶q相干态及其性质 总被引:1,自引:0,他引:1
本文以新的参数化方式引入第二类奇偶 q 相干态,并定义了 q 压缩概念。第二类奇偶 q 相干态的压缩效应和反聚束效应类似于奇偶相干态,但存在q压缩效应。 相似文献
5.
多模辐射场的广义非线性高阶差压缩——N次方X压缩的一般理论 总被引:136,自引:55,他引:81
本文在发展现有理论的基础上,提出了多模(2q模)辐射场的广义非线性高阶差压缩(即N次方X压缩)的定义,给出N次方X压缩效应的压缩度的计算公式,并对N-X最小测不准态和N-X压缩最小测不准态等进行了详细讨论.指出,MarkHilery在文献6中所提出的有关双模辐射场的“差压缩”的定义,仅仅是本文所提出的多模辐射场的广义非线性高阶差压缩(即N次方X压缩)的一般性定义在q=1、N=1条件下的特例. 相似文献
6.
高Q Kerr介质腔中非关联双模相干态光场与V型三能级原子相互作用系统中光场的等阶Y压缩效应 总被引:22,自引:9,他引:13
本文利用多模压缩态理论,详细研究了高Q Kerr介质腔中非关联双模相干态光场与V型三能级原子相互作用系统中双模光场的一次和二次等阶Y压缩效应,结果表明:1)等阶Y压缩特性强烈地依赖于Kerr介质的三阶非线性极化系数(x)和双模光场中各模的平均光子数n1、n2;当x<1,n1=n2<1时,不产生等阶Y压缩效应;而当x=2.5、5、10以及n1=n2=2、5时,光场可呈现出强烈的一次及二次等阶Y压缩效应;2)在x以及n1、n2相同的条件下,不同压缩阶次的等阶Y压缩效应的时间演化曲线的压缩周期与压缩阶次成反比,压缩度的幅度则随压缩阶数的升高而迅速下降;3)在平均光子不变(即n1=n2恒定),但Kerr介质不同(即x变化)的条件下,相同压缩阶数的等阶Y压缩效应的Y压缩度曲线的时间演化周期与Kerr介质的三阶非线性化系数x成反比,压缩度的幅度则随Kerr介质的三阶非线性极化系数x的增大而增强;4)等阶Y压缩效应的持续时间以及等阶Y压缩度的大小等强烈地依赖于Kerr介质的非线性程度和光场强度;一般而言,Kerr介质的非线性程度越高(即x越大),并且光场越强(即n1=n2取值越大),等阶Y压缩效应持续时间就越短,等阶Y压缩度就越大. 相似文献
7.
单光束对“对一苯并噻唑基尾式铁(Ⅲ)卟啉”非线性光学特性的研究 总被引:2,自引:1,他引:1
本文用单光束研究了“对一苯并喀基尾式铁(Ⅲ)卟淋”的非线性光学特性,发现该样品有反饱和吸收效应及由其导致的光眼幅特征;用Z扫描法测得其三阶非线性极化率达到1.53×10-12esu. 相似文献
8.
一种新型的多模虚偶相干态光场的等阶N次方Y压缩与等阶N次方H压缩 总被引:45,自引:25,他引:20
本文利用新近建立的多模压缩态理论,详细研究了一种新型的多模虚偶相干态光场|Ψi,e(2)>q的广义非线性等阶N次方Y压缩与等阶N次方H压缩特性.结果发现:1)态|Ψi,e(2)>q是一种典型的多模非经典光场,当压缩阶数N为奇数时,态|Ψi,e(2)>q在一定条件下总可呈现出周期性变化的、任意阶的等阶N次方Y压缩效应;当腔模总数q与压缩阶数N这两者的乘积q·N为奇数时,则在一定条件下态|Ψi,e(2)>q又可呈现出周期性变化的、任意阶的等阶N次方H压缩效应.2)态|Ψi,e(2)>q的等阶N次方Y压缩与等阶N次方H压缩效应这两者的压缩程度和压缩深度分别与几率幅γq(e)、压缩参数Rj、各模的初始相位φj(或者各模的初始相位和 φj)、压缩阶数N以及腔模(指纵模)总数q等呈较强的非线性关联,等阶N次方H压缩效应与上述诸参量之间的非线性关联程度要比等阶N次方Y压缩效应的更强.3)多模虚偶相干态光场|Ψi,e(2)>q与多模偶相干态光场|Ψ,e>q及多模复共轭偶相干态光场|Ψ*,e(2)>q这后两者的等阶N次方Y压缩效应和等阶N次方H压缩效应的压缩条件和压缩特性正好相反,这种现象就称为相反压缩. 相似文献
9.
把一维q变形振子的结论推广到D维q变形振子体系,得到了D维q变形振子体系的哈密顿算符形式,并求出了其本征值和在坐标象中的本征函数.结果显示,这是一个非线性振子. 相似文献
10.
多模复共轭奇、偶相干态光场的N次方Y压缩与N次方H压缩 总被引:28,自引:39,他引:28
利用新近提出的多模辐射场的广义非线性等阶高阶压缩理论,对多模复共轭奇、偶相干态光场的N次方Y压缩与N次方H压缩特性进行了详细研究.结果发现:①多模复共轭奇相干态光场,压缩阶数N为偶数时,只存在N-Y最小测不准态;而当腔模总数q与压缩阶数的乘积q·N为偶数时,只存在N-H最小测不准态;此外,无论N及q·N为何值,不呈现N次方Y压缩与N次方H压缩效应.②多模复共轭偶相干态光场在一定条件下可呈现出周期性变化的任意阶的N次方Y压缩与N次方H压缩效应.③多模偶相干态光场与多模复共轭偶相干态光场两者的压缩效果和压缩特性完全相同,这种现象称为“压缩简并”. 相似文献
11.
12.
Signs change of nonlinear refractive index in ZnSe is observed by employing a modified double 4f imaging system at the wavelength of 800 nm using picosecond pulses with different pulse energies. This process results from the competition of the bound electronic nonlinear refraction and the free carrier refraction. At low intensity, positive nonlinear refraction is obtained, which is attributed to bound electrons. As the increase of laser beam intensity, the nonlinear refractive index become small, and changes to negative. This is ascribed to free carriers generated by two-photon absorption. Additionally, the nonlinear refractive index of bound electron and the refractive index change of free carrier are determined unambiguously by a simple method. 相似文献
13.
A spherically symmetric lens with a negative refractive index, which can be invisible from the point of view of geometrical optics, is considered. Expressions describing the profile of the refractive index and ray trajectories in the lens, as well as some results of numerical modeling of plane wave scattering by the lens in the rigorous statement of the problem, are presented. It is detected that, unlike in the case of an invisible lens with a positive refractive index, the minima of the radar cross section in the forward direction corresponding to invisibility for the lens with a negative index occur at integer, rather than semi-integer, values of the electric radius, and that their depth is smaller because of the astigmatism associated with focusing of rays on the axis. Some results characterizing influence of losses in the lens on the level of the radar cross-section minima are also presented. 相似文献
14.
含负折射率缺陷的一维光子晶体的杂质带 总被引:1,自引:1,他引:0
利用传输矩阵方法研究了含负折射率缺陷的一维光子晶体的透射谱.以19个周期的1/4波堆存在3个负折射率缺陷的光子晶体为例进行了数值计算.结果表明:如果改变缺陷的折射率,缺陷模之间的耦合作用将发生改变,带隙中形成的杂质带也随之改变; 当这个折射率取适当值时,在禁带中出现多个尖锐的透射峰,与正折射率缺陷构成的杂质带不同. 相似文献
15.
16.
基于光波在宇称-时间(PT)对称波导中传输的理论模型, 数值研究了亮孤子在呈高斯分布的PT对称克尔非线性平板波导中的传输和控制. PT对称波导, 要求波导的折射率分布呈偶对称, 而增益/损耗分布呈奇对称. 结果表明: 当波导的折射率分布强度为正时, PT对称波导的中心折射率最大, 即使没有自聚焦克尔非线性效应, PT对称波导也可以束缚光波, 形成波浪形光束且长距离传输; 当折射率分布强度为负时, PT对称波导的中心折射率最小, 光波的传输方向发生偏移. 而增益/损耗分布可控制光波的偏移方向: 增益/损耗分布强度为正, 光波向左偏移; 强度为负, 光波向右偏移; 强度为零时, 光波被分为两束. 且当折射率分布强度为负时, 可以很好地抑制相邻亮孤子间的相互作用. 该研究结果可为未来PT对称波导在全光控制方面的应用提供一定的理论依据. 相似文献
17.
The investigation of nonlinear optical characteristics of ethanol solution doped with is presented. A large thermal-induced third-order nonlinear refractive index up to silver nanoparticles 1.941× 10^-7 cm2/W is obtained from the mixed solution under 488-nm continue wave (CW) laser irradiation, which may result from surface plasmon resonance (SPR) enhancement effect of silver nanoparticles as well as high thermo-optic coefficient and low thermal conductivity of ethanol. Obvious spatial self-phase modulation and influence of thermal-induced negative lens effect are observed when a beam propagates through this solution, indicating promising applications such as optical limiting, beam flattening, and so on. 相似文献
18.
19.
Based on the coupled-mode theory, the propagation of light pulses is studied analytically for a system of an infinite number of tunnel-coupled parallel equidistant waveguides of optically nonlinear materials; in the considered system, waveguides with a positive refractive index alternate with waveguides with a negative refractive index. Partial solutions to a system of nonlinear equations describing the evolution of these pulses are found in the case in which fields in adjacent waveguides differ only in the phase factor. For a solitary wave formed by coupled wave packets localized each in its own waveguide, these solutions describe the stationary propagation in a definite direction. It is shown that the coupling strength between waveguides has an effect on the propagation rate of the obtained stationary pulses. 相似文献
20.
A. V. Ilyenkov A. I. Khiznyak L. V. Kreminskaya M. S. Soskin M. V. Vasnetsov 《Applied physics. B, Lasers and optics》1996,62(5):465-471
We report on an experimental and numerical investigation of the process of spontaneous optical vortices nucleation in a wave front of a laser beam passed through a photorefractive LiNbO3 : Fe crystal with self-induced nonlinear lens. The complex lens structure produces mainly defocusing of the beam passing through the crystal due to a negative variation of the refractive index, whereas side parts of the lens have a positive sign of refractive-index variation and partially focus the beam. The resulting wave-front distortions lead to a phase bifurcation occurring at a certain distance after the crystal when the amplitude of the light wave becomes zero. We study in detail the process of edge dislocation nucleation and its decay in the near field producing a pair of unity-charged opposite-sign screw dislocations. After birth, they spread along dislocation axes as stable objects. 相似文献