Compact, reliable asymmetric optical configuration for cost-effective fabrication of multiplex dot matrix hologram in anti-counterfeiting applications

This study presents a compact optical configuration that can generate a multiplex dot-matrix hologram with complex interlaced images for anti-counterfeiting applications on valuable paper. Varying the orientation of the interference plane can enable the multiplex hologram to be recorded without changing the interference angle of two laser beams. With its simple asymmetric optical setup, a multiplex hologram with many interlaced images can be efficiently fabricated, increasing the cost of imitation. Experimental details of the asymmetric optical setup are also described.     

Extremal Convex Planar Sets

Each convex planar set K has a perimeter C, a minimum width E, an area A, and a diameter D. The set of points (E,C, A^1/2, D) corresponding to all such sets is shown to occupy a cone in the non-negative orthant of R⁴with its vertex at the origin. Its three-dimensional cross section S in the plane D = 1 is investigated. S lies in a rectangular parallelepiped in R³. Results of Lebesgue, Kubota, Fukasawa, Sholander, and Hemmi are used to determine some of the boundary surfaces of S, and new results are given for the other boundary surfaces. From knowledge of S, all inequalities among E, C ,A, and D can be found.     

束流线性耦合效应的初步研究

在储存环的束流传输系统中,斜四极场和纵向螺线管场是引起束流线性耦合的主要原因.由于这种耦合,使得束流的幅度和发射度发生交换,引起束流横向包络的增大,严重的将造成束流损失.从Betatron运动方程出发研究了斜四极场和螺线管场存在时束流的幅度耦合效应,分析了斜四极场存在时束流发射度的变化.     

Decay distribution of spontaneous emission from atoms in one-dimensional photonic crystal

Spontaneous emission behavior from atoms (or molecules) in one-dimensional photonic crystal with a defect is investigated. Taken all the TE and TM modes into account, the normalized spontaneous emission rate of the atom is calculated as a function of the position of the atom in the crystal. Results for both nonabsorbing dielectric structure and absorbing dielectric structure are presented. With the increase of the thickness of the defect in which the atoms are embedded, the oscillations of the spontaneous emission rate versus the position of the atom become dense and the lifetime distribution becomes narrow and sharp. The PC effect may lead to the coexistence of both accelerated and inhibited decay processes.     

Enhancement of the Kerr effect for a quantum dot in a cavity

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.     

Analytical study of a flattened Gaussian beam through multi-apertured optical imaging systems of B = 0

By using the methods of the matrix decomposition and expansion of the hard-edged aperture function into a finite sum of complex Gaussian functions, the recurrence propagation expressions for a flattened Gaussian beam (FGB) through multi-apertured optical imaging systems of B = 0 are derived and illustrated with numerical examples. Comparisons with the straightforward numerical integration of the Collins formula and with the previous work are made. It is shown that the main advantages of our methods and results are the more accuracy and great reduction of computer time.     

The Novel Y-Branch With Two Reflectors

A novel Y-branch waveguide with two reflectors is proposed. The normalized transmitted power for the branching angle of 50°is greater than 70%, which is higher than conventional Y-branch with such wide angle.     

非因子化方法研究D~+→ ■~0K~+衰变(英文)

在领头阶和αs 修正阶 ,用QCD因子化方法 ,并对它的软胶子效应用光锥QCD求和规则分析D+ → K0 K+ 衰变过程 ,我们分析发现朴素因子化方法的结果远离实验结果 ,QCD因子化方法结果靠近实验结果 ,但是 ,在QCD因子化方法中 ,若考虑软胶子效应 ,其结果与实验结果相一致 .另外 ,计算发现 ,软胶子效应在该衰变道中有相当大的贡献 ,因此不能被忽略