ABSTRACT
In the field of laser development, researchers have always been challenged to move to the shorter wavelength part of the spectrum. In the period shortly after the invention of the laser, research activities were mainly concentrated on systems operating in the visible and near-infrared part of the spectrum. This choice of spectrum is understandable if we look at the required instrumental conditions: in particular, the optical components and technology for the required input powers were already available. The appropriate excitation method and input power could be realized at that time with classical instruments available in any wellequipped laboratory. Futhermore, the excitation power for reaching the laser threshold decreases rapidly with longer wavelength. Some near-infrared lasers like the CO2 and Nd:YAG lasers could, therefore, be developed energetically as mature high-power instruments for large-scale applications in roughly one decade. Being so successful and driven by potential new applications, similar systems in the UV, VUV and even XUV were desired.
