TIME-RESOLVED PICOSECOND SPECTROSCOPY OF THE RESONANT SECONDARY RADIATION OF F-CENTERS IN KCL

The linear polarization (P-HL) Of hot luminescence (HL) composing of t he resonant secondary radiation of the F centers has been measured usi ng a time-resolved picosecond spectroscopy over the whole Stokes waven umber Omega range. The P-HL holds constant value of about 40% until th e onset of ordinary luminescence (OL), from where it decreases to vani shingly small with decrease of Omega. This implies that the optically excited F center relaxes down along the 2p-like adiabatic potential en ergy surface (APES) trough, and transits to the 2s-like APES trough to form the relaxed excited state (RES). The lattice relaxation time and the dynamical transition rime are ultra fast estimated to be less tha n 15 psec.