Tunable giant Faraday rotation of exciton in semiconductor quantum wells embedded in a microcavity

The Faraday rotation of an exciton in a GaAs quantum well (QW) embedded in a microcavity is investigated theoretically. The authors find that the Faraday rotation is enhanced remarkably by the microcavity, with a magnitude about two orders of magnitude larger than that of a single QW without microcavity. The Faraday rotation can be tuned by changing the incident angle of the pump and probe lights, or by varying the temperature or an external electric field. With an appropriate detuning between the cavity mode of the pump and probe lights, the Faraday rotation spectrum displays a strongly asymmetric line shape, which can easily be detected experimentally.

Ultrafast geometric manipulation of electron spin and detection of the geometric phase via Faraday rotation spectroscopy

Time-resolved Faraday rotation spectroscopy is currently exploited as a powerful technique to probe spin dynamics in semiconductors. We propose here an all-optical approach to geometrically manipulate electron spin and to detect the geometric phase by this type of extremely sensitive experiment. The global nature of the geometric phase can make the quantum manipulation more stable, which may find interesting applications in quantum devices.

Nonlinear Faraday Waves in a Parametrically Excited Circular Cylindrical Container

In the cylindrical coordinate system, a singular perturbation theory of multiple-scale asymptotic expansions was developed to study single standing water wave mode by solving potential equations of water waves in a rigid circular cylinder, which is subjec

Rotation Numbers Of Invariant Manifolds Around Unstable Periodic Orbits For The Diamagnetic Kepler Problem

In this paper, a method to construct topological template in terms of symbolic dynamics for the diamagnetic Kepler problem is proposed. To confirm the topological template, rotation numbers of invariant manifolds around unstable periodic orbits in a phase space are taken as an object of comparison. The rotation numbers are determined from the definition and connected with symbolic sequences encoding the periodic orbits in a reduced Poincare section. Only symbolic codes with inverse ordering in the forward mapping can contribute to the rotation of invariant manifolds around the periodic orbits. By using symbolic ordering, the reduced Poincare section is constricted along stable manifolds and a topological template, which preserves the ordering of forward sequences and can be used to extract the rotation numbers, is established. The rotation numbers computed from the topological template are the same as those computed from their original definition.

Distribution, stability, bifurcations and catastrophe of steady rotation of a symmetrical heavy gyroscope with viscous-liquid-filled cavity

The number, the angles of orientation and the stability in Rumyantsev Movchan's sense of oblique steady rotations of a symmetric heavy gyroscope with a cavity completely filled with a uniform viscous liquid, possessing a fixed point 0 on its symmetric axis. are given for various values of the parameters. By taking the square of the upright component of the angular momentum M2 as a control parameter, three types of bifurcation diagrams of the steady rotations, two types of jumps and two kinds of local catastrophes, one being the symmetric reduced cusp type and the other being of the symmetric reduced butterfly type, are obtained. By taking account of the M2-damping owing to the moment of unavoidable faint friction, two different modes for the gyroscope, initially in a stable quasi-steady upright rotation with a nutation angle theta(s) equal to zero, to topple over are found.

Adiabatic compression of plasma with purely toroidal rotation

A variational method is developed to find approximate solutions to the generalized Grad-Shafranov equations for an adiabatic compression of the plasma with toroidal rotation, via the expansion in Fourier series in poloidal angle of the flux surface coordinates. The numerical results, which are carried out by the present method and by the usual two-dimensional method for a static equilibrium state, agree well.

Variational method for adiabatic compression of plasma with poloidal and toroidal rotation

A variational method is developed for adiabatic compression of plasma with both poloidal and toroidal rotation.

参数激励圆柱形容器中的非线性Faraday波

在柱坐标系下，通过奇异摄动理论的多尺度展开法求解势流方程，研究了垂直强迫激励圆柱形容器中的单一模式水表面驻波模式．假设流体是无粘、不可压且运动是无旋的，在忽略了表面张力的影响下，用两变量时间展开法得到一个具有立方项以及底部驱动项影响的非线性振幅方程．对上述方程进行了数值计算，计算的结果显示了在不同驱动振幅和驱动频率下，会激发不同自由水表面驻波模式，从等高线的图像来看，和以往的实验结果相当吻合．

Pulse temporal cleaner based on nonlinear ellipse rotation by using BK7 glass plate

We report a new pulse cleaning technique to enhance the contrast ratio of intense ultra-short laser pulses. A pulse temporal cleaner based on nonlinear ellipse rotation by using BK7 glass plate is developed, and a contrast ratio improvement of two orders of magnitude for the milli-joule level femtosecond input pulses is demonstrated, the total transmission efficiency of the pulse cleaner is 16.7%.

基于偏振度检测的光纤电流传感方案

本文提出了一种将光学谐振腔中多次来回反射所产生的法拉第旋转积累效应转化为光学信号偏振度变化的光纤电流传感方案。这种方案的主要优点是可以克服环境等因素的扰动带来偏振态变化所产生的影响。文中对所提出方案的特性进行了简单的理论分析和模拟计算，并给出了相应的实验结果验证。

反射型磁光多层膜隔离器的频率响应及宽容性研究

通过传输矩阵法分析了材料介电常数的变化对于单缺陷结构的磁光多层膜隔离器性能的响，并提出了一种多缺陷结构的磁光多层膜结构．同单缺陷结构相比，多缺陷结构的旋转角的频谱响应带宽有很大增加，对于材料介电常数变化的宽容性得到了一个数量级的提高．同时这种多缺陷的结构对于膜层厚度的变化和入射角度也有很好的宽容性．