The static pull-in instability of beam-type micro-electromechanical systems is theoretically investigated. Two engineering cases including cantilever and double cantilever micro-beam are considered. Considering the mid-plane stretching as the source of the nonlinearity in the beam behavior, a nonlinear size-dependent Euler-Bernoulli beam model is used based on a modified couple stress theory, c...

We demonstrate experimentally all-optical beam steering in modulated photonic lattices induced optically by three-beam interference in a biased photorefractive crystal. We identify and characterize the key physical parameters governing the beam steering and show that the spatial resolution can be enhanced by the additional effect of nonlinear beam self-localization.

The ion-hose instability is a transverse electrostatic instability which occurs on electron beams in the presence of a low-density ion channel. In the DARHT-2 accelerator, the 2 kA, 2 microsecond beam pulse produces an ion channel through impact ionization of the residual background gas ( 1:5 10 7 torr average). A calculation of the linear growth by R. J. Briggs indicated that the instability c...

Photorefractive crystals are electro-optic dielectrics that host a small amount of photosensitive impurities. Light propagation leads to the generation of outof-equilibrium mobile charge, that, in order to reach a stable electro-static configuration, redistributes throughout the crystal. The ensuing space-charge field, modifying electro-optically the crystal index of refraction, changes the tra...

Assembling nonlinear dynamic models of structures is the goal of numerous research and development organizations. Such a predictive capability is required in the development of advanced, high-performance aircraft structures. Specifically, the ability to predict the response of complex structures to aero-acoustic loading has long been a United States Air Force goal. Sonic fatigue has plagued the...