Entire Transmission in Negative Directions through a Single Layer of Nanorods

We numerically investigate the regulation of beam direction by a single layer of high electrical permittivity nanorods with two kinds of cross-arranged radii. It is found that an oblique incident optical beam transmits more than 95% with a wide range wavelength of 80 nm near 1550 nm in a negative direction. In particular the efficiency can be up to 100% around the wavelength of 1550nm at a wide-range angle. The results are very promising for designing subwavelength optical elements to realize beam steering in optical integrated circuits.     

激光演示牛顿半环

用激光照射牛顿半环来演示薄膜台阶的等厚干涉现象和测定薄膜厚度。     

利用周期信号驱动Chua电路实现相同步

我们在实验上和理论上对周期信号驱动的混沌电路的相同步问题进行了研究。我们选择三类周期信号作为驱动信号，包括Chua电路产生的周期信号，正弦信号和脉冲信号。改变驱动信号的频率、振幅和脉冲信号的占空比，在周期信号和混沌信号存在小的频率失配的条件下，驱动信号的振幅在适当的变化范围内，以及脉冲信号的占空比在适当的变化范围内，都可以获得相同步。甚至当占空比小到3%的情况下，仍然可以得到相同步。特别是这类脉冲信号的控制在实际中是有意义的。     

Intermittencies in complex Ginzburg-Landau equation by varying system size

Dynamical behaviour of the one-dimensional complex Ginzburg--Landau equation (CGLE) with finite system size $L$ is investigated, based on numerical simulations. By varying the system size and keeping other system parameters in the defect turbulence region (defect turbulence in large $L$ limit), a number of intermittencies new for the CGLE system are observed in the processes of pattern formations and transitions while the system dynamics varies from a homogeneous periodic oscillation to strong defect turbulence.     

Experimental observation of partial amplitude death in coupled chaotic oscillators

The dynamics of coupled Lorenz circuits is investigated experimentally. The partial amplitude death reported in {\em Phys. Rev.} E {\bf 72}, 057201 (2005) is verified by physical experiments with electronic circuits. With the increase of coupling constant, the coupled circuits undergo the transition from the breakdown of both the reflection symmetry and the translational symmetry to the partial amplitude death. Its stability is also confirmed by analysing the effects of noise.     

Millimeter Propagation and High Confinement in Rhombus-Based Hybrid Plasmonic Waveguides

A hybrid plasmonic waveguide, consisting of two dielectric nanowires symmetrically put at the opposite corner angles of a rhombic metM, is proposed and numerically analyzed by the finite-element method. Simulations show that the present waveguide can achieve the millimeter propagation distance （1244 μm） and deep subwavelength mode area （5.5 × 10-3 μm2）, simultaneously. Compared with the previous hybrid waveguides based on cylinder nanowires or fiat films, the rhombie corner angles enable our waveguide to achieve both longer propagation distance and smaller mode area. This is due to the enhanced coupling between the dielectric guided mode in nanowires and the surface plasmon polariton mode at rhombic surface. Furthermore, the extreme confinement near the rhombic corner angles can strengthen the light-matter interaction greatly and make the present waveguide useful in many applications, such as nonlinear photonics, high-quality nanolazers and nanophotonic waveguides.     

耦合混沌同步和多路保密通信

本文针对混沌系统在通信中具有理想的保密作用，讨论了离散多振子耦合混沌系统的特性和两个耦合混沌系统的同步行为，结果表明，两个耦全合混沌系统通过简单调制能很快同步，并且具有通信保密性和多路传输特性。     

混沌专题系列研究性实验介绍

介绍了北京邮电大学物理实验中心在教学内容改革中开发的混沌专题系列实验.通过简单的、易于实现的力学和电路系统介绍混沌,将复杂的学术问题转化成了可以为不同层次学生所接受的研究性实验课题,激发了学生的实验兴趣,将科研成果直接转化为了教学实践.     

Experimental observation of a multirhythmic pattern in chains of Rossler circuits

<正>The influence of parameter mismatches on multirhythmic patterns in chains of coupled Rossler circuits are explored experimentally.The parameter mismatches in coupled chaotic oscillators are found to help form a kind of multirhythmic pattern as reported in chains of biological coupled oscillators[Phys.Rev.Lett.92 228102].Moreover,a new type of multirhythmic pattern based on the envelope of time series is observed.     

Compensation of chromatic dispersion for full-duplex ROF link with vector signal transmission using an optical phase shifter

We demonstrate the theory of chromatic dispersion(CD)-induced constellation rotation(CR) in a radio-over-fiber(ROF) link and a method for compensation. We also propose a 60 GHz full-duplex ROF system with vector signal transmission including no CD effect. The evaluation of 5 Gb/s 16 quadrature amplitude modulation signal transmission shows that the CD-induced CR can be entirely overcome due to the proposed method which is simply implemented through an optical phase shifter. The proposed ROF schedule is not only applicable for V-band(57–64 GHz) but also fits for W-band(75–110 GHz), or any other bandwidth.