The Stanford 2 GeV electron-positron storage ring is equipped with 20 beam position monitors. The principle of beam coupling is analysed and a calculation is made for the sensitivity to beam current and position, as well as for the intrinsic distortion of this type of monitor. Beam orbit coordinates are reconstructed by scanning the monitor's four electrode signals and the 20 stations around th...

This paper studies interfacial mechanical behavior of laminate beams, consisting of two piezoelectric facial sheets and an elastic core. The study is based on coupled multi-filed finite element formulation. The emphasis is placed on mechanical and electric behavior of interfaces between piezoelectric material and elastic material, including effect of geometrical parameters, stress distribution ...

A series of beam experiments is being planned in the Jefferson Lab FEL driver accelerator in order to study multi-pass beam breakup instabilities in the machine and to test the predictions of the numerical code TDBBU. The tests are extensions of previously performed or proposed experiments, and will be considerably more sensitive with the present configuration. The experiments will include: a) ...

Here we investigate theoretically and numerically the coupling between surface plasmon polaritons (SPPs) in monolayer graphene sheet arrays that have a period much smaller than the wavelength. We show that when the collective SPP is excited with an out-of-phase illumination, the beam tends to propagate toward the opposite direction of the Bloch momentum, reflecting a negative coupling between t...

| The electric and magnetic polarizabilities of an aperture are its important characteristics in the theory of aperture coupling and diiraction of EM waves. The beam coupling impedances due to a small discontinuity on the chamber wall of an accelerator can also be expressed in terms of the polarizabilities of the discontinuity. The po-larizabilities are geometrical factors which can be found by...

We analyze reflexive photorefractive coupling of an information-bearing beam carrying several distinct spatiotemporal features, with emphasis on the coupling-induced change in the mutual spatial coherence. We formulate equations describing evolution of the mutual correlation functions between different features and discuss their solutions both in the full two-dimensional case and in the limit l...

Theoretical study of free space coupling to high-Q whispering gallery modes (WGMs) are presented in circular and deformed microcavities. Both analytical solutions and asymptotic formulas are derived for a circular cavity. The coupling efficiencies at different coupling regimes for cylindrical incoming wave are discussed, and the maximum efficiency is estimated for the practical Gaussian beam ex...

We show by numerical simulation as well as by measurements on negative-index metamaterial wedge samples, that the unavoidable stepping of the refraction interface-due to the finite unit-cell size inherent to metamaterials-can give rise to a well-defined diffracted beam in addition to the negatively refracted beam. The direction of the diffracted beam is consistent with elementary diffraction th...

Pump-induced dynamical tunneling has been observed in free-space resonant optical pumping of a deformed microcavity by employing excitation spectroscopy. A focused-pump beam was injected into the cavity by refraction and then coupled to a high-Q cavity mode via dynamical tunneling. Pump-coupling efficiency as high as 50% and an effective coupling constant responsible for the tunneling were obta...

In this work, we study the behavior of elliptical reflectors in nanophotonic integrated circuits in the context of two-dimensional multimode Gaussian beam. We show that the transformation of the beam profile at the input/output waveguide mouths, and the transformation of the beam profile at the reflector can be described in terms of 2D Hermite-Gaussian (HG) beam modes under first order approxim...