AVS 54th International Symposium | |
Plasmonics Topical Conference | Tuesday Sessions |
Session PL-TuP |
Session: | Plasmonics Poster Session |
Presenter: | A. Passian, Oak Ridge National Laboratory |
Authors: | A. Passian, Oak Ridge National Laboratory A. Lereu, ICFO-The Institute of Photonic Sciences, Spain R..H. Farahi, Oak Ridge National Laboratory N.F. van Hulst, ICFO-The Institute of Photonic Sciences, Spain T.G. Thundat, Oak Ridge National Laboratory |
Correspondent: | Click to Email |
Thermoplasmonic processes in continuous and nanostructured metallic thin films The development of optical integrated components such as modulators, filters or switches, has been of continuing interest during recent decades, also in conjunction with developing a new generation of opto-electronic components. In this context, the capability of modulation of light by light naturally appears as a basic goal to achieve toward the emergence of such components. In parallel tremendous progresses have been made in nanofabrication such that nanostructured thin films and surface features may be accomplished with nanometric control. We introduce the concept of surface plasmon (SP) mediated thermo-optical processes to achieve optical modulation. In the first part, SP excitation, supported in thin gold films in the Kretschmann configuration, is demonstrated to lead to a new form of low-frequency modulation of light by light. Thermo-optical processes are shown to be the origin of such a modulation. We report experimental results of the surface response regarding a coupling between several spectrally different Gaussian beams, where a modulated infrared beam is taken as the pump beam and multiple visible continuous beams represent the probes. In the second part, to achieve higher modulation frequency rate, we study nanostructured thin films and nanoparticles where it is expected to see higher dissipation of thermal effects and bring the optical aspect to light. In order to get first some insights, we investigate using spectroscopy and near field scanning optical microscopy (NSOM) the optical response of gold nanostructures placed on a transparent substrate by electron beam lithography. In a second step, a modulated pump beam will be applied to the nanostructured film/nanoparticles and the local illumination from the NSOM tip will be used as a probe signal. We are aiming to achieve higher modulation frequency as well as to utilize lower excitation power. Moreover, the limitation of the excitation power corresponds well with the damage threshold of the nanostructures, a parameter to be taken into account.