Ultrafast nonlinear spectroscopy with spatially confined fields

The combination of pulse shaping techniques for ultrashort laser pulses with nanoplasmonics leads to applications in the spatiotemporal control of electronic excitations with subwavelength precision. First, a method of finding shaped pulses for spatial selective excitation of individual nanostructures is presented. Second, double quantum coherence, a two‐dimensional spectroscopic technique, yields the energies of single excitons and biexcitons and shows correlations between them. Through combining the spectroscopy with localization of optical fields we obtain more detailed information about the excitonic energies and couplings.