共查询到20条相似文献,搜索用时 15 毫秒
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2.
Based on the well-known electron coherent tunneling phenomenon, by simulation, a photonic tunneling filter fabricated in an
optical waveguide is proposed. The Bragg grating structure is applied as the photonic barrier. Two photonic barriers confine
a coherent resonance cavity or photon-quantum-well. We report an asymmetric-barrier structure with opposite phase. In this
configuration, the central tunneling wavelength is exactly the same as the Bragg wavelength of the grating, independent of
the photon-quantum-well dimension. The photon-quantum-well length can be adjusted to make the tunneling peak interval fall
to a desired spacing. The photon barrier length is responsible for the filter bandwidth. As an application, an asymmetric
grating photon tunneling filter with International Telecommunication Union grid is demonstrated. 相似文献
3.
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
4.
推导了光束在Kerr介质、屏蔽介质及光伏介质的一维光子晶格中演化的二能级形式,给出了光束在这三种光折变介质中传播时二能级系统的经典哈密顿形式.以屏蔽介质为例,做出了空间相图,当非线性参数变化时,空间相图的拓扑改变.给出了空间相图的拓扑发生改变时,非线性参数的临界值.数值研究了非线性Landau-Zener(LZ)隧穿,得到非线性参数与LZ隧穿率的关系,发现非线性参数大于0时增强了隧穿,而非线性参数小于0时抑制了隧穿.
关键词:
二能级模型
光折变介质
光子晶格
非线性Landau-Zener隧穿 相似文献
5.
We propose a photonic realization of tunneling control for two strongly correlated particles moving on a one-dimensional lattice, based on light transport in a square waveguide lattice with a periodically curved axis. We show the photonic analogue of dynamic localization of correlated particles and suggest the possibility to coherently suppress particle interaction. 相似文献
6.
Propagation and tunneling of light through photonic barriers formed by thin
dielectric films with continuous curvilinear distributions of dielectric
susceptibility across the film, are considered. Giant heterogeneity-induced
dispersion of these films, both convex and concave, and its influence on
their reflectivity and transmittivity are visualized by means of exact
analytical solutions of Maxwell equations. Depending on the cut-off
frequency of the film, governed by the spatial profile of its refractive
index, propagation or tunneling of light through such barriers are examined.
Subject to the shape of refractive index profile the group velocities of EM
waves in these films are shown to be either increased or deccreased as
compared with the homogeneous layers; however, these velocities for both
propagation and tunneling regimes remain subluminal. The decisive influence
of gradient and curvature of photonic barriers on the efficiency of
tunneling is examined by means of generalized Fresnel formulae. Saturation
of the phase of the wave tunneling through a stack of such films (Hartman
effect), is demonstrated. The evanescent modes in lossy barriers and
violation of Hartman effect in this case is discussed. 相似文献
7.
F. Xi L. Hu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2012,66(2):33
We investigate the properties of electromagnetic wave propagating in a one-dimensional photonic crystal (PC) consisting of
two metamaterials with different dispersive model. The reflection gaps of metamaterials multilayer system are independent
of the incident angle. Not only TE wave but also TM wave, the omnidirectional reflection gaps exhibit the same behavior with
different incident angle for metamaterials as double negative material. We also observed that the frequency regimes of zero-transmission
bands are different for TE and TM wave with the same incident angle, when one of metamaterials is the permittivity negative
(ε < 0) and the other is the double negative. Correspondingly, we show that the result can be act as an efficient polarization
splitter. At last, we discuss the resonant tunneling effect. If the total reflection condition is satisfied, the resonant
tunneling effect is enhanced as the incident angle increases, even though the propagation wave is evanescent wave in the single
layer medium. 相似文献
8.
We review our theoretical advances in quantum tunneling of BoseEinstein condensates in optical traps and in microcavities. By employing a real physical system, the frequencies of the pseudo Goldstone modes in different phases between two optical traps are studied respectivdy, which are tile crucial feature of the non-Abelian Joseptmon effect. When the optical lattices are under gravity, we investigate the quantum tummling in the "Wannier-Stark localization" regime and "Lan(lau Zener tunneling" regime. We finally get the total decay rate and the rate is valid over the entire range of temperatures. At high temperatures, we show how the decay rate reduces to the appropriate results for the classical thermal activation. At hltermediate temperatures, the results of tile total decay rate are consistent with the thermally assisted tunneling. At low temperatures, we obtain the pure quantmn tunneling ultimately. And we study the alternating-current and direct-current (ac and de) photonic 3osephson effects in two weakly linked microcavities containing ultracold two-level atones, which allows for direct observation of the effects. This enables new investigations of the effect of maw-body physics in strongly coupled atom-cavity systems and provides a strategy for constructing novel interference devices of coherent photons. In addition, we propose the experimental protocols to observe these quantmn tunneling of Bose- Einstein condensates. 相似文献
9.
Trompeter H Krolikowski W Neshev DN Desyatnikov AS Sukhorukov AA Kivshar YS Pertsch T Peschel U Lederer F 《Physical review letters》2006,96(5):053903
We report on the first experimental observation of photonic Bloch oscillations and Zener tunneling in two-dimensional periodic systems. We study the propagation of an optical beam in a square lattice superimposed on a refractive index ramp. We observe oscillations of the beam inside the first Brilloin zone and tunneling of light from the first to the higher-order bands of the lattice band gap spectrum. 相似文献
10.
Trompeter H Pertsch T Lederer F Michaelis D Streppel U Bräuer A Peschel U 《Physical review letters》2006,96(2):023901
We experimentally investigate photonic Zener tunneling between the bands of a waveguide array by directly monitoring the propagating light inside this structure. For strong transverse index gradients we observe Zener breakdown as regular outbursts of radiation escaping from the Bloch oscillations. Tunneling to higher order photonic bands and Bloch oscillations in different bands have been detected. 相似文献
11.
We theoretically demonstrate how to acquire the full bandgap spectrum of a photonic lattice of arbitrary profile. Focusing on the 1D case in the presence of a linear refractive index acceleration and employing a multiscale analysis, we show that each photonic band can be directly mapped by the light evolution in the lattice, whereas the size of each gap corresponds to the tunneling rate. We verify the analytical results with numerical simulations and discuss experimental realizations of this technique for dispersive spectroscopy. 相似文献
12.
T. Feng L. Fan Y. H. Li C. L. Zhang Z. Feng 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(3):315-319
In this paper, the tunneling phenomenon occurring in the photonic
heterostructure consisting of single-negative (SNG) metamaterials is
experimentally studied. First, the SNG metamaterials are fabricated using
coplanar waveguide with lumped-element series capacitors and shunt inductors
loading. Then, the tunneling phenomenon occurring in the photonic
heterostructure containing SNG media is experimentally demonstrated.
Moreover, the insensitivity of the tunneling frequency to the
breakdown of periodicity of phonotic crystals was also illustrated. 相似文献
13.
We study tunneling modes in a one-dimensional photonic crystal (1DPC) with multilayered periodic structures containing dispersive anisotropic single-negative (ASNG; permittivity- or permeability-negative) metamaterials. A defect layer is introduced into the proposed structure, and some unusual properties are found in contrast with that of a tunneling mode in PCs with isotropic single-negative (SNG) gaps. 相似文献
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15.
We investigate the resonance tunneling modes of photonic double quantum well made of two photonic crystals with two different single-negative materials. It is found that these resonance modes split pairs, due to a coupling between two photonic wells. It is observed that when two photonic quantum wells are far away from each other, resonance modes appear as a single peak. And the quality factors of the transmittance resonance peaks can be greatly improved by increasing the period number of the outer barrier. The effects of the losses coming from ENG and MNG materials on the resonance modes are also specifically explored. 相似文献
16.
T.B. Wang 《Physics letters. A》2008,373(1):169-172
Complete band gaps are found in one-dimensional photonic crystals composed of negative-permittivity and negative-permeability materials. The mechanism of these complete band gaps, unlike the Bragg complete gaps formed by interferences of forward/backward propagating waves, originate from the evanescent wave tunneling in the single-negative materials is reported for the first time. Moreover, it is also reported for the first time that both Bragg complete gaps and evanescent wave tunneling complete gaps exist in a three-constituent one-dimensional photonic structure simultaneously. 相似文献
17.
By means of the modal expansion method with an R-matrix propagation algorithm, effects of the coupling between resonance photonic states on the resonance tunneling through a double quantum well structure are investigated. We examine the effects on the transmission spectra due to variation of the second well width and middle barrier thickness. Drastic change of the tunneling spectra is found and analyzed when the wells are filled with left-hand media. 相似文献
18.
We demonstrate coherent destruction of tunneling (CDT) in optically induced three-dimensional photonic lattices. By fine-tuning the lattice modulation, we show unusual behavior of beam propagation, including light tunneling inhibition, anomalous diffraction, and negative refraction mediated by zero or negative coupling in the waveguide arrays. Image transmission based on CDT is also proposed and demonstrated. Our experimental results are in good agreement with our theoretical analyses. 相似文献
19.
Under total reflection conditions, it typically seems as though light waves will be reflected completely on the interface; in actuality, the waves can penetrate the medium as evanescent waves. In this paper, we present a twinned lattice photonic crystal with a unit cell composed of AB layers and their mirror. We assume that the refractive index n 0 of the input and output end is equal to n B and larger than n A . We first demonstrate the dependence of band structure on the incidence angle and normalized wavelength, in which the resonant tunneling bands are exposed. We then draw a comparison of bands between ABBA and AB. To conclude, we discuss the resonant tunneling effect in the twinned lattice photonic crystal under the total reflection conditions. As incidence angle increases, the resonant tunneling band ultimately vanishes completely. 相似文献
20.
A. Shvartsburg V. Kuzmiak G. Petite 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,72(1):77-88
A flexible multi-parameter exactly solvable model of potential profile,
containing an arbitrary number of continuous smoothly shaped barriers and
wells, both equal or unequal, characterized by finite values and continuous
profiles of the potential and of its gradient, is presented. We demonstrate
an influence of both gradient and curvature of these potentials on the
electron transport and spectra of symmetric and asymmetric double-well (DW)
potentials. The use of this model is simplified due to one to one
correspondence between the algorithms of calculation of the transmittance of
convex barriers and energy spectra of concave wells. We have shown that the
resonant contrast between maximum and minimum in over-barrier reflectivity
of curvilinear barrier exceeds significantly the analogous effect for
rectangular barrier with the same height and width. Reflectionless tunneling
of electrons below the bottom of gradient nanostructures forming concave
potential barriers is considered. The analogy between dynamics of electrons
in gradient fields and gradient optics of heterogeneous photonic barriers is
illustrated. 相似文献