The linear and nonlinear optical properties of nanostructured materials have been the object of numerous studies due to the possibility of tailoring these properties by manipulation of their material structure; composition, particle size, and shape are some of the parameters considered for tuning the nonlinear response. The localized surface plasmon resonances encountered for metallic inclusions in dielectric media have been thoroughly investigated. Most systems consist of randomly placed nanoparticles contained in another medium. Due to the randomness of the system, the response of such a system can be seen as an incoherent addition of the individual response of each nanoparticle. By contrast, an ordered array of nanoelements in principle would allow a response that is the coherent addition of the individual element responses, and hence large effective nonlinear parameters can be expected that will also exhibit the symmetry properties of the structure. In this work, we will present a study of the nonlinear optical properties of ordered arrays of a single layer of metallic nanostructures and their use as field-enhancement devices for biosensing applications and to control the radiative emission efficiency of quantum emitters in close proximity. We present a detailed study of the refractive and absorptive nonlinear optical properties of these composites employing the z-scan technique with picosecond and femtosecond pulses. The dependences on wavelength, polarization, and irradiance of the nonlinear response are explored, and the thermal and electronic contributions are resolved. Time-resolved techniques are also employed to study the dynamics of the response.
File in questo prodotto:
Non ci sono file associati a questo prodotto.