An extended study of vibrational and electronic transitions, relaxation and energy-transfer processes of simple and complex defects in alkali halides is planned. Isolated molecular defects, excited with various ir laser or electronic excitation techniques, will be explored in the spectral and temporal domains for ir vibrational fluorescence, existing in weak or strong competition to multi-phonon or multi-roton relaxation or intermolecular vibrational energy transfer processes. Association of molecular defects with F centers form pair- configurations, which under F-electron excitation can produce efficient electron-vibration (E-V) energy transfer into the molecular modes leading to multi-step vibrational emission. Under variation of host materials, molecules and optical techniques the kinetics and physical mechanism of the E-V transfer process will be studied and clarified. The ability of these defect-pairs to produce vibrational superfluorescence and visible-light-pumped vibrational solid state lasers will be systematically explored and developed. Besides these vibrationally emitting systems, strong electronic transitions of new F-aggregate centers will be studied with the aim of developing color center lasers with improved-stability cw as well as psec mode-locked operation over an extended near ir tuning range. Single mode operation of these lasers will be used for high-resolution hole-burning experiments in various vibrational and electronic defects. Their active work on order/disorder transitions of pure and mixed alkali-cyanides will be extended, particularly towards new optical questions and techniques.
