| Summary: | This thesis concerns the measurement and characterization of the Surface Plasmon Drag Effect (SPDE) in metallic structures and its application to the electrical detection of surface plasmon polaritons (SPPs). We demonstrate that SPPs absorbed in a metallic structure generate an electric current, which polarity depends on the propagation direction of the absorbed SPP, without the need of any applied voltage. We investigate the effect in gold and silver thin films of different thickness and on various metallic bilayers, which are deposited on right angle prisms and hemispheres to allow coupling of light to SPP through the Kretschmann-Raether configuration. We then simultaneously measure the angular spectrum of the reflected light and the electric current generated by the effect. The accuracy of the experiment allow us to determine the effect efficiency and thus to quantitatively compare different samples. In an attempt to clarify the mechanism giving rise to the current generation, we compare our experiments with existing models of the Photon Drag Effect (PDE). This is a similar phenomenon mediated by photon absorption where the current is the result of momentum transfer from the photon to conduction electrons. We find that the model qualitatively predicts our results and thus SPDE can be interpreted as the result of quasimomentum transfer from SPPs to the electrons, but care must be taken for considering the prediction of the model quantitatively. In addiction, we discovered that the effect shows local efficiency enhancement and even change of the current polarity in the presence of films with defects. Those results suggest a different interpretation to previous literature results and overall deepen the understanding of the phenomenon. A clear comprehension of the mechanisms leading to current generation is crucial for designing future applications in sensing and photonic circuitry. Despite the low efficiency in the visible range, in fact, this effect can be attractive since it promises to have an ultrafast response, to retain its sensitivity at longer wavelengths and has the peculiar ability of sensing the propagation direction of the SPP.
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