Ricerc@Sapienza

A computational study of the electromechanical response of micro-structure engineered two port surface acoustic wave delay lines on gallium arsenide is presented. The influence on the results of geometrical, material, and mesh parameters is also discussed. Furthermore, experimental results are provided to validate the numerical study. The device consists of two interdigital transducers composed of 40, 80, and 120 pairs of electrodes, respectively, with a pitch pidt=8μm and distant didt=1502μm.

We demonstrate the control of enhanced chiral field distribution at the surface of hybrid metallo-dielectric nanostructures composed of self-assembled vertical hexagonal GaAs-based nanowires having three of the six sidewalls covered with Au. We show that weakly-guided modes of vertical GaAs nanowires can generate regions of high optical chirality that are further enhanced by the break of the symmetry introduced by the gold layer.