Single-shot autocorrelator for KrF subpicosecond pulses based on two-photon fluorescence of cadmium vapor at X = 508 nm

By excitation of cadmium vapor with a high-peak-power KrF excimer laser pulse, fluorescence of an atomic transition at X = 508 nm is induced by a two-photon ionization process followed by fast recombination. The nonlinear response of the medium is used to develop a simple single-shot autocorrelator for subpicosecond KrF excimer laser pulses operating down to intensities of less than 109W/cm.2 We have measured 360-fs (FWHM) pulses at X = 248 nm with a time resolution of 15 fs

Untersuchung von Beschichtungsverfahren fuer optische Laserkomponenten in den Wellenlaengenbereichen UV/VUV und NIR. Teilvorhaben: Herstellung verlustarmer Beschichtungen fuer den Bereich 130nm bis 250nm Abschlussbericht

The working package of this project was focused on the production of low loss dielectric coatings for the UV/VUV-spectral range. Besides conventional boat evaporation, ion-assisted deposition and ion beam sputtering were employed. These ion techniques have the advantage of being able to produce films at low substrate temperatures with low scatter losses. With conventional thermal evaporation, mirrors based on fluorides for excimer-laser-applications could be produced with low absorption losses and high laser-induced damage thresholds. High substrate temperatures of more than 400 C are required. With the ion techniques, coatings with low scatter losses, high packing density and high environmental stability could be achieved at substrate temperatures of less than 100 C. On the other hand IAD- and IBS-mirrors show high absorption losses and low damage thresholds in the UV/VUV-range. Nevertheless, the mirrors with the highest reflectivity are IBS-coatings based on oxides, due to their low scatter losses. At longer wavelengths, the advantages of the ion techniques are more pronounced. Mirrors for the wavelength of 514nm could be produced with the IBS-process with total losses of less than 10ppm. Furthermore, IBS-mirrors for the NdYAG-laser show damage thresholds comparable with the best conventional systems. (orig.)SIGLEAvailable from TIB Hannover: F95B2226+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman