Our main field of research is the investigation of free clusters. We study the nonlinear response of clusters in strong laser fields, optical properties of neutral clusters in ultracold helium droplets and photoelectron electron spectroscopy of mass-selected metal clusters using VUV- free electron laser (FLASH) radiation.

In addition, the project “clusters on surfaces” investigates nano-structures on surfaces and clusters on surfaces.

Research on free clusters

Small particles and clusters in a molecular beam are benchmark systems for nanostructured materials and offer the unique chance to explore the development of many-body effects in finite quantum systems. In our research we concentrate on electronic and optical properties of metal clusters. To realize these studies, advanced laser spectroscopy techniques as for example resonant multiphoton ionizaton and photoelectron spectroscopy are applied. Our research program covers a wide range of the light-matter interaction starting from ground state properties up to the strongly nonlinear regime using various methods. Pulsed soft xrays from the free electron laser FLASH at DESY in Hamburg are used to study electron core-level shifts in mass selected clusters in order to determine e.g. electronic decay mechanisms in particles of given size. With the helium nanodroplet technology a versatile tool is provided to prepare clusters in a weakly interacting environment at ultralow temperatures. Applying intense and structured optical laser pulses, metal and rare gas clusters as well as hydrogen microjets are probed, giving informations about the nonlinear response of laser-generated finite plasmas. The aim of these studies is to entirely characterize and finally control the many-body Coulomb explosion in this brute interaction by applying tailored laser pulses. Charge and momentum of the emitted particles as well as short wavelength emission are analyzed using various techniques like high resolution ion mass spectrometry, angular resolved photoelectron spectroscopy and soft xray detection. A new focus of our research is the application of intense, tailored laser pulses to generate novel structures for implementations in the medical domain.

Josef Tiggesbäumker

Karl-Heinz Meiwes-Broer


Our laboratories are equipped with the following experimental methods:


Previous projects

  • Light 2 Hydrogen
  • Nano 4 Hydrogen
  • Remedis
  • DFG priority programm 1153
  • Ultra short laser pulses for material processing
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