In my research group we use ultra-short laser pulses , durations down to femtoseconds, to study the dynamics of elementary excitations (electrons, excitons, vibrations, ...) in nanomaterials. The goal is to use this information to manipulate more rationally the nanoscale degrees of freedom (size, shape, ..) to enable new applications of these materials in photonics, e.g. to absorb or emit light in photo-detectors or lasers respectively.