Fabricating active plasmonic structures by combining laser-, electron- and ion-beam techniques

The burgeoning interest in sub-wavelength metal optics is fueled by applications ranging from cancer therapy and proteomics to opto-electronics and novel photovoltaic materials. The optical properties of nanoscale metallic structures are determined not only by the electromagnetics of localized and propagating surface plasmons, but also by the details of metal nanoparticle size, shape and spatial arrangement, and dielectric environment. This paper presents several ways in which interesting plasmonic structures and applications are made possible by nanoscale materials synthesis and structuring techniques based on pulsed laser and electron-beam deposition, electron-beam lithography and focused ion-beam nanomachining. Examples include (1) using a focused ion beam to create arrays of sub-wavelength holes in which the extraordinary optical transmission effect can be switched; (2) fabricating gold::VO2 composite nanoparticles to measure the size dependence of the metal-insulator transition in vanadium dioxide using surface-enhanced Raman scattering; and (3) the construction of heterostructures in which excitons can be coupled to surface plasmons.