Pump–probe microscopy: Visualization and spectroscopy of ultrafast dynamics at the nanoscale

• DOI: 10.1016/j.chemphys.2015.07.006
• Publication Date: 2015-07-10T17:50:45Z
• Authors: Erik M. Grumstrup; Michelle M. Gabriel; Emma E.M. Cating; Erika M. Van Goethem; John M. Papanikolas
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract Excited state dynamics at the nanoscale provide important insight into the influence of structural features such as interfaces, defects, and surfaces on material properties. Pump–probe microscopy combines the spatial resolution of far-field optical microscopy with the temporal resolution of ultrafast spectroscopy, and has emerged as a powerful technique for characterizing spatial variation in dynamical phenomena across nanometer length scales. It has helped correlate dynamical phenomena with specific structural features in a variety of materials, shedding light on how excited state behaviors can dramatically differ from one member of the ensemble to the next, and even at different points within a single structure. It has also enabled direct imaging of transport phenomena such as free carrier diffusion, exciton migration and plasmon propagation in nanostructures. This ability to observe individual objects provides unique insight into complex materials where heterogeneous behavior makes it difficult, if not impossible, to reach clear and quantitative conclusions.