1 Lasers and Light-Matter-Interaction

Within this research area, fundamental theoretical and experimental research on light-matter interaction is combined with the development of novel laser-driven light sources. The theoretical work focuses on non-linear optical spectroscopies of charge, spin, and energy flow on attosecond to femtosecond time-scales. Research is performed over a wide range from simple gas phase molecules to biologically relevant molecules in gas and liquid phase, including chiral systems, and to condensed matter systems. Goals include the control of these dynamics with tailored, wave-form controlled laser fields. The work includes both the development of concepts and tools to push the frontiers of nonlinear ultrafast light-matter interaction towards resolving and controlling electric-field driven dynamics at THz to PHz rates. Ab-initio tools for extreme nonlinear optics are developed, including coupling Maxwell equation solvers with accurate simulations of the microscopic response, aiming in particular at supporting MBI’s experimental efforts towards optimization of mid-IR driven high harmonic generation, delivering XUV and X-ray light with tailored temporal and polarization properties.

Experimental activities in this research area encompass research on both “primary“ and “secondary” laser sources, the latter made possible by the availability of suitable primary laser sources. The primary source development includes the continued development of OPCPA systems at long wavelength, as well as the development of long wavelength CPA systems, exploiting the availability of novel Cr- and Ho-based gain materials, accompanied by concentrated efforts towards CEP stabilization and power scaling of these light sources, in combination with post-compression to the sub-picosecond and/or few-cycle regime. This represents an alternative approach towards the realization of long-wavelength driver lasers for HHG. MBI´s research on secondary source development spans the entire wavelength regime from the THz to the XUV and X-ray domain. Its principal goals are (i) the generation of broadband mid-IR continua derived from available few-micron drivers for applications, e.g., in 2D vibrational spectroscopy, (ii) the realization of intense THz sources and associated field-enhancement devices for use in field-driven processes, (iii) the generation of ultrashort (≤5 fs) deep- and vacuum-UV pulses, for use in pump-probe spectroscopy, including the development of new methods for generating ultrashort pulses around or even below 200 nm, (iv) efficient and stable high harmonic generation beyond the water window for applications and (v) the generation of circularly polarized attosecond pulses for studies of ultrafast chiral and spin dynamics.