Imaging the extent of plasmon excitation in Au nanowires using pump-probe microscopy

Knowledge of how energy and charge carriers move in nanoscale systems is essential for engineering efficient devices. In this Letter, we demonstrate a technique to directly image dynamics in nanostructures based on laser scanning transient absorption microscopy, which provides near diffraction-limited spatial resolution and ultrafast time resolution. The capabilities of the technique are demonstrated by experiments on propagating surface plasmon polariton modes of Au nanowires, although these measurements can be used to study a variety of fluorescent and nonfluorescent systems.