Multiscale beam evolution and shaping in corrugated plasmonic systems.

We analyze, theoretically and experimentally, the dynamics of the wavepackets in plasmonic beaming devices, and show that the beam evolution in this class of structures is a multiscale phenomenon, which initiates in the near-field proximity of the device, develops continuously over a new length scale many times the wavelength of the light, and is completed well into the far-field of the system. We develop a quantitative description of the light evolution in the beaming structures and verify our theoretical predictions with experiments. Our analytical results are utilized to develop plasmonic geometries for shaping the mid-field beam evolution, and experimental results from these structures are demonstrated.