Optical-field enhancement and confinement for an asymmetrically illuminated nanoscopic Au tip suspended over a planar Au substrate is investigated both numerically and experimentally. The spatial field distribution of the tip-sample system was calculated using the full 3D finite-difference time-domain method. The calculation enables investigation of the effects of the substrate-tip placement, angle of incidence, and spectral response. The tip plasmon response leads to a significant (up to ~70 times) local field enhancement between the tip and substrate. The enhancement is found to be extremely sensitive to the tip-sample separation distance. Tip-enhanced Raman scattering experiments were performed and the numerical results provide a consistent description of the observed field localization and enhancement.

We investigate the tasks of general morphological tagging, diacritization, and lemmatization for Arabic. We show that for all tasks we consider, both modeling the lexeme explicitly, and retuning the weights of individual classifiers for the specific task, improve the performance.

Plasmon-enhanced transmission of light incident on a periodic array of nanoscale, asymmetric cruciform patterns is demonstrated. The corresponding transmission spectra are shown to be polarization dependent and possess unique properties, such as the existence of isosbestic points for which the transmission is polarization insensitive. Transmission peaks corresponding to localized surface plasmon resonances and extended surface plasmons are also identified.

The physical mechanism of He-ion-based exfoliation in Z-cut LiNbO3 is investigated. Rutherford backscattering/channeling, nuclear-reaction analysis, and transmission electron microscopy are used to examine the compositional and structural changes caused by deep ion implantation followed by thermal annealing. Lattice disruption, He-bubble formation, and Li depletion are observed in the implantation region, as well as the onset of exfoliation. The implications of these observations for the crystal ion slicing method are discussed.