Investigation of nanoparticle ensembles using polarization tailored light beams

Nanoparticles find a wide range of applications in physics, biology and medicine. In such applications, their optical properties defining the interaction with the impinging light play an important role. Light beams with a non-homogeneous or tailored polarization distribution at the nanoscale, such as tightly focused radially or azimuthally polarized light beams, have been proven to be an excellent and versatile tool for studying the optical response of nanoscopic dielectric or metallic particles. Due to the spatial degree of freedom in their electric field and intensity distribution, such beams allow for a higher level of controllability when exciting the nanostructures under study providing a huge variety of possible coupling scenarios within a single beam configuration.

To further tune and tailor the scattering properties of nanoscopic systems, nanoparticles can be arranged to form small particle ensembles. The effective optical response of such a nanosystem is governed by the individual building-blocks and their interaction with each other. Particle ensemble can exhibit exotic resonances which cannot be studied with standard excitation schemes. In contrast, polarization tailored light beams can provide the necessary spatial field distribution allowing for the detailed study of these higher order resonances. We fabricate nanoparticle ensembles, generate the corresponding light fields for excitation and plan to perform experimental studies of the optical response of the system under investigation.