The Raschke group pursues experimental nonlinear and ultrafast nano-optics. The goal is to understand and control the light-matter interaction in solids on nanometer length scales and femtosecond time scales. Combining scanning probe microscopy with ultrashort laser pulse excitation as developed by his group provides access to the natural length and time scales of the elementary electronic, vibrational, and structural excitations. This allows them to address the fundamental processes underlying correlated electron phenomena in complex oxides, semiconductor heterostructures, or the phase behavior in polymer nano-composites. They apply concepts of optical antennas and surface plasmon and phonon polaritons to confine, sculpt, and control light spectrally, nanometer spatially, and on time scales of a single-optical cycle. They also explore new optical phenomena and forces unique to the optical near-field, including extreme nonlinear optics, and strong light matter interaction.
Nonlinear and ultrafast nano-optics, control light-matter interaction in solids on nanometer length scales and femtosecond time scales, combining scanning probe microscopy with ultrashort laser pulse excitation, study of correlated electron phenomena in complex oxides, semiconductor heterostructures, phase behavior in polymer nano-composites; optical antennas, surface plasmon polaritons, extreme nonlinear optics, strong light matter interaction