Different approaches of microoptical beam shapers for high-power UV- and VUV-lasers (fluorine dimer laser, higher harmonics of Ti:sapphire laser) were studied theoretically and experimentally. Refractive microaxicon- arrays consisting of profiled thin dielectric layers or bulk material reliefs were fabricated by vapor deposition and structure transfer into substrates by reactive ion etching. Extremely small conical angles (minimum 0.015°) and relatively low roughness (rms < 3 nm) were obtained. With elements of defined non-spherical profiles (in particular Gaussian phase distributions) sub-beams of very extended depth of focus are generated.

Beam propagation was simulated by Rayleigh-Sommerfeld diffraction theory. It was shown theoretically, that an apodization-like spatial frequency filtering might be realized by the layer absorption if the material is properly chosen. The application of Bessel-beam array generators to the concept of angular-tolerant Shack-Hartmann sensors for short wavelengths is discussed as well.

Dr. Ruediger Grunwald finished his study of physics at Humboldt University Berlin in 1982 with a diploma thesis on plasma spectroscopy. In 1986, he prepared a doctoral thesis on UV multiphoton dissociation of molecules and spectroscopy of free radicals. From 1982 to 1992, he worked at the Central Institute for Optics and Spectroscopy in Berlin on excimer laser development, laser spectroscopy, frequency stabilized CO2 lasers and unstable resonators. From 1992 to 1998, he was a project manager at the Society of Applied Optics (GOS) in Berlin and developed thin-film optics for short-pulse excimer and solid-state lasers.

Since 1998, he is with the Max-Born-Institute for Nonlinear Optics and Short-Pulse Spectroscopy Berlin. In projects on laser diodes he studied resonance enhanced frequency conversion and developed new collimating microoptics. Currently, his interest is concentrated on shaping and characterization of ultrashort- pulse VUV lasers and nonlinear optics of nanocrystalline glasses. Recent highlights were the first detection of few-cycle optical X-waves and the characterization of femtosecond laser pulses by wavefront autocorrelation. Since 2001, he was several times at Laval University Quebec in the frame of a Canadian-German Collaboration project.