共查询到20条相似文献,搜索用时 15 毫秒
1.
O. V. Borovkova V. E. Lobanov A. K. Sukhorukova A. P. Sukhorukov 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(5):718-720
Regularities of anisotropic discrete diffraction in a cascade-induced lattice formed by two crossed pump waves in a quadratically nonlinear medium have been studied. The transition from diffraction of a signal beam in free space to discrete diffraction with further capture into a waveguide in a defocusing lattice with an increase in the pump wave intensity has been traced. Diffraction-free propagation of a tilted beam is described. 相似文献
2.
We report the first experimental demonstration of ring-shaped photonic lattices by optical induction and the formation of discrete solitons in such radially symmetric lattices. The transition from discrete diffraction to single-channel guidance or nonlinear self-trapping of a probe beam is achieved by fine-tuning the lattice potential or the focusing nonlinearity. In addition to solitons trapped in the lattice center and in different lattice rings, we demonstrate controlled soliton rotation in the Bessel-like ring lattices. 相似文献
3.
N. Piovella 《The European physical journal. Special topics》2012,203(1):127-136
A Bose-Einstein condensate in a high-finesse ring cavity scatters the photons of a pump beam into counterpropagating cavity
modes, populating a bi-dimensional momentum lattice. A high-finesse ring cavity with a sub-recoil linewidth allows to control
the quantized atomic motion, selecting particular discrete momentum states and generating atom-photon entanglement. The semiclassical
and quantum model for the 2D collective atomic recoil lasing (CARL) are derived and the superradiant and good-cavity regimes
discussed. For pump incidence perpendicular to the cavity axis, the momentum lattice is symmetrically populated. Conversely,
for oblique pump incidence the motion along the two recoil directions is unbalanced and different momentum states can be populated
on demand by tuning the pump frequency. 相似文献
4.
We investigate both experimentally and theoretically the interaction between a light beam and a photonic lattice optically induced with partially coherent light. We demonstrate a clear transition from two-dimensional discrete diffraction to discrete solitons in such a partially coherent lattice and show that the nonlinear interaction process is associated with a host of new phenomena including lattice dislocation, lattice deformation, and creation of structures akin to optical polarons. 相似文献
5.
We demonstrate anisotropic enhancement of discrete diffraction and formation of discrete-soliton trains in an optically induced photonic lattice. Such discrete behavior of light propagation was observed when a one-dimensional stripe beam was launched appropriately into a two-dimensional lattice created with partially coherent light. Our experimental results are corroborated with numerical simulations. 相似文献
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We demonstrate that both the linear (diffraction) and the nonlinear dynamics of two-dimensional waveguide arrays are considerably more complex and versatile than their one-dimensional counterparts. The discrete diffraction properties of these arrays can be effectively altered, depending on the propagation Bloch k-vector within the first Brillouin zone of the lattice. In general, this diffraction behavior is anisotropic and therefore permits the existence of a new class of discrete elliptic solitons in the nonlinear regime. 相似文献
8.
E. Smirnov C.E. Rüter D. Kip K. Shandarova V. Shandarov 《Applied physics. B, Lasers and optics》2007,88(3):359-362
Single- and double-periodic one-dimensional photonic lattices are formed in lithium niobate using both titanium in-diffusion
and holographic grating recording. We investigate linear band structures and diffraction properties of such superlattices
and observe a decrease of discrete diffraction with increasing modulation depth of the second superimposed lattice. In weakly
modulated superlattices with tailored diffraction properties, our results demonstrate the formation of discrete solitons having
a propagation constant inside the extra mini-gap formed inside the Brillouin zone.
PACS 42.65.Tg; 42.70.Qs; 42.82.Et 相似文献
9.
A. K. Sukhorukova A. P. Sukhorukov V. E. Lobanov O. V. Borovkova 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(1):13-16
A method for cascade generation of a periodic lattice in a medium with quadratic nonlinearity is proposed. Such a lattice is induced as a result of interference of two or four crossed fundamental-frequency waves. Numerical simulation of the discrete diffraction of a signal beam coupled to one of the lattice waveguides is performed. With an increase in the modulation depth of the refractive index, the signal wave is trapped in the waveguide. 相似文献
10.
P. Zhang N. K. Efremidis A. Miller P. Ni Z. Chen 《Applied physics. B, Lasers and optics》2011,104(3):553-560
We report on our recent theoretical and experimental studies of three-dimensional (3D) photonic lattice structures which are
established in a bulk nonlinear crystal by employing different optical induction techniques. These 3D photonic lattices bring
about new opportunities for controlling the flow of light via coupling engineering originated from the lattice modulation
along the beam propagation direction. By fine tuning the lattice parameters, we observe a host of unusual behaviors of beam
propagation in such reconfigurable 3D lattices, including enhanced discrete diffraction, light tunneling inhibition—better
known as coherent destruction of tunneling (CDT), anomalous diffraction, negative refraction, as well as CDT-based image transmission.
In addition, we propose and demonstrate a new way of creating 3D ionic-type photonic lattices by controlled Talbot effect. 相似文献
11.
Longhi S 《Physical review letters》2006,97(11):110402
An exactly-solvable model for the decay of a metastable state coupled to a semi-infinite, tight-binding lattice, showing large deviations from exponential decay in the strong coupling regime, is presented. An optical realization of the lattice model, based on discrete diffraction in a semi-infinite array of tunneling-coupled optical waveguides, is proposed to test nonexponential decay and for the observation of an optical analog of the quantum Zeno effect. 相似文献
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平顶光端面抽运DPL中热效应对输出功率的影响 总被引:1,自引:0,他引:1
用平顶光束描述由多根光纤紧密排列耦合并经透镜整形后的抽运光分布,给出了平顶光束的光强分布,对晶体热效应引起的热致衍射损耗随抽运功率和抽运光束半径的变化规律进行了数值计算,讨论了晶体热效应引起的热致衍射损耗对基横模高斯光束输出功率的影响,并实验验证了基横模高斯光束输出功率随抽运功率的变化规律.结果表明:热致衍射损耗使基横模高斯光束输出功率明显降低.随着抽运光束半径的增大,热致衍射损耗减小,对基横模高斯光束输出功率的影响就减小;抽运功率越大,热致衍射损耗越大,对基横模高斯光束输出功率的影响就越大. 相似文献
14.
In this Letter, by means of using discrete zero curvature representation and constructing opportune time evolution problems, two new discrete integrable lattice hierarchies with n-dependent coefficients are proposed, which relate to a new discrete Schrödinger nonisospectral operator equation. The relation of the two new lattice hierarchies with the Volterra hierarchy is discussed. It has been shown that one lattice hierarchy is equivalent to the positive Volterra hierarchy with n-dependent coefficients and another lattice hierarchy with isospectral problem is equivalent to the negative Volterra hierarchy. We demonstrate the existence of infinitely many conservation laws for the two lattice hierarchies and give the corresponding conserved densities and the associated fluxes formulaically. Thus their integrability is confirmed. 相似文献
15.
《Physics letters. A》2006,349(6):439-445
In this Letter we give a new integrable four-field lattice hierarchy, associated to a new discrete spectral problem. We obtain our hierarchy as the compatibility condition of this spectral problem and an associated equation, constructed herein, for the time-evolution of eigenfunctions. We consider reductions of our hierarchy, which also of course admit discrete zero curvature representations, in detail. We find that our hierarchy includes many well-known integrable hierarchies as special cases, including the Toda lattice hierarchy, the modified Toda lattice hierarchy, the relativistic Toda lattice hierarchy, and the Volterra lattice hierarchy. We also obtain here a new integrable two-field lattice hierarchy, to which we give the name of Suris lattice hierarchy, since the first equation of this hierarchy has previously been given by Suris. The Hamiltonian structure of the Suris lattice hierarchy is obtained by means of a trace identity formula. 相似文献
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17.
Xi-Xiang Xu 《Physics letters. A》2010,374(3):401-410
An integrable coupling family of Merola-Ragnisco-Tu lattice systems is derived from a four-by-four matrix spectral problem. The Hamiltonian structure of the resulting integrable coupling family is established by the discrete variational identity. Each lattice system in the resulting integrable coupling family is proved to be integrable discrete Hamiltonian system in Liouville sense. Ultimately, a nonisospectral integrable lattice family associated with the resulting integrable lattice family is constructed through discrete zero curvature representation. 相似文献
18.
XU Quan TIAN Qiang 《理论物理通讯》2009,51(1):153-156
We restrict our attention to the discrete two-dimensional monatomic β-FPU lattice. We look for two- dimensional breather lattice solutions and two-dimensional compact-like discrete breathers by using trying method and analyze their stability by using Aubry's linearly stable theory. We obtain the conditions of existence and stability of two-dimensional breather lattice solutions and two-dimensional compact-like discrete breathers in the discrete two- dimensional monatomic β-FPU lattice. 相似文献
19.
In this paper,we focus on the construction of new(1+1)-dimensional discrete integrable systems according to a subalgebra of loop algebra A 1.By designing two new(1+1)-dimensional discrete spectral problems,two new discrete integrable systems are obtained,namely,a 2-field lattice hierarchy and a 3-field lattice hierarchy.When deriving the two new discrete integrable systems,we find the generalized relativistic Toda lattice hierarchy and the generalized modified Toda lattice hierarchy.Moreover,we also obtain the Hamiltonian structures of the two lattice hierarchies by means of the discrete trace identity. 相似文献
20.
LOU Ci-bo TANG Li-qin SONG Dao-hong WANG Xiao-sheng XU Jing-jun CHEN Zhi-gang 《Frontiers of Physics》2008,3(1):1
The study of wave propagation in periodic systems is at the frontiers of physics, from fluids to condensed matter physics, and from photonic crystals to Bose-Einstein condensates. In optics, a typical example of periodic system is a closely-spaced waveguide array, in which collective behavior of wave propagation exhibits many intriguing phenomena that have no counterpart in homogeneous media. Even in a linear waveguide array, the diffraction property of a light beam changes due to evanescent coupling between nearby waveguide sites, leading to normal and anomalous discrete diffraction. In a nonlinear waveguide array, a balance between diffraction and self-action gives rise to novel localized states such as spatial “discrete solitons” in the semi-infinite (or total-internal-reflection) gap or spatial “gap solitons” in the Bragg reflection gaps. Recently, in a series of experiments, we have “fabricated” closely-spaced waveguide arrays (photonic lattices) by optical induction. Such photonic structures have attracted great interest due to their novel physics, link to photonic crystals, as well as potential applications in optical switching and navigation. In this review article, we present a brief overview on our experimental demonstrations of a number of novel spatial soliton phenomena in light-induced photonic bandgap structures, including self-trapping of fundamental discrete solitons and more sophisticated lattice gap solitons. Much of our work has direct impact on the study of similar discrete phenomena in systems beyond optics, including sound waves, water waves, and matter waves (Bose-Einstein condensates) propagating in periodic potentials. 相似文献