Electronic readout of optically excited surface plasmons

Abstract

Leveraging thermal losses as a useful consequence of surface plasmons in metal nanostructures has gained traction in recent years. This thermalization of hot electrons also induces a resistance change to an applied bias current, which we use to realize an all electronic readout of surface plasmons. The interplay of the plasmonic k-vector dependence and the applied bias current allows us to distinguish between linear polarizations of an incident laser beam for polarimetry and polarization imaging uses. This illustrates the potential applications this technique offers as a fully CMOS compatible plasmonic sensor. Moreover, we demonstrate an electronic signal that depends on the delay between two laser pulses on ultrafast timescales, providing insight into the highly non-equilibrium dynamics of the hot electron distribution inside the metal. Using an electronic approach to surface plasmons broadens access and simplifies existing applications, while simultaneously opening the door to new pathways for developing integrated sensors for processes on ultrafast timescales.