Optical gratings are used extensively for beamsteering in the visible and IR range of the spectrum. Change in the dielectric permittivity of a semiconductor medium resulting from the excitation of a nonequilibrium electron-hole plasma makes it possible to extend this technique to MMW frequencies. A photo-induced plasma grating (PIPG) can be easily rewritten by changing the illumination pattern,...

We consider a carbon nanotube gated slightly away from the half-filled π-band, in the presence of an externally applied periodic potential. We show that the electron states can become locked by the potential when the electron density (counted from half-filling) corresponds to a rational number of electrons per potential period. At such densities, excitation gaps open up in the spectrum. When ga...

introduction: in recent decades, several monte carlo codes have been introduced for research and medical applications. these methods provide both accurate and detailed calculation of particle transport from linear accelerators. the main drawback of monte carlo techniques is the extremely long computing time that is required in order to obtain a dose distribution with good statistical accuracy. ...

A novel mechanism for generating large (> 1 GeV/m) accelerating wakes in a plasma is considered. We employ two slightly detuned counter-propagating laser beams, an ultra-short timing pulse and a long pump, which exchange photons and deposit the recoil momentum into the plasma electrons. A rapidly rising electron current is thereby generated, inducing an plasma wake with phase velocity equal to ...