Using a focused ion beam, we patterned epitaxial graphene on SiC into an array of graphene nanoribbons as narrow as 15 nm by optimizing the Ga(+) ion beam current, acceleration voltage, dwell time, beam center-to-center distance and ion dose. The ion dose required to completely etch away graphene on SiC was determined and compared with the Monte Carlo simulation result. In addition, a photodete...

A simple scheme to steer optical beams is proposed. The basic idea is to impose a sinusoidal phase modulation on the optical beam and then propagate it in a nonlinear Kerr medium. Spatial phase modulation splits the input beam into multiple subbeams, while the nonlinear medium shapes a particular subbeam into a spatial soliton in such a way that most of the beam power appears in a narrow beam w...

We propose an original nonlinear beam cleaning fiber laser architecture to obtain high energy pulses with a good beam quality and a narrow linewidth. The output beam of a large core Er:Yb co-doped multimode fiber amplifier (M(2) approximately 6, 220 microJ) is converted into a near diffraction limited beam (M(2) = 1.6) through a stimulated Brillouin scattering injection seeded beam cleanup proc...

A smart antenna for mobile applications incorporating an array of ± 45 polarised stacked patch elements 4 columns wide excited by a multi-beamforming and beam shaping network is described. Four narrow overlapping beams, one wide “broadcast channel” beam and right and left shaped beams can be provided. The later shaped beams are to provide high capacity coverage in a specific narrow angular sect...

Many scattering experiments in which a beam radiation or particles are sent into a material that scatters them have a number of features in common. (We shall use the word radiation to refer to the thing that is scattered.) • The radiation is a wave that satisfies a wave equation. • The incident beam is collimated (moving in one particular direction). • The incident beam is monochromatic (a narr...

Automated monitoring of circadian rhythms is an efficient way for gaining insight into oscillation parameters like period and phase for the underlying pacemaker of the circadian clock. Measurement of the circadian rhythm of phototaxis (swimming towards light) exhibited by the green alga Chlamydomonas reinhardtii has been automated by directing a narrow and dim light beam through a culture at re...

We have fabricated narrow channel Si-MOSFETs for electron transport studies at low temperature. The fabrication process combines optical lithography for large structures and high resolution e-beam lithography for narrow gates. The smallest working devices have a 0.14 pm wide gate. This paper reports the fabrication process and gives some examples of the quantum transport phenomena observed in t...