Abstract

Recently in studies of fluorescence excitation and persistent spectral hole burning (PSHB) of single molecules in crystalline environment spectral jumps have been observed at 1.5 K providing new insights into the low temperature dynamics of the condensed phase [1]. The connection between PSHB and the phonon-induced dynamics in asymmetric double-well-potentials (DWP) has been used in a photophysical model of PSHB explaining also phonon detection by refilling of a spectral hole observed after irradiation with nanosecond heat pulses [2]. These DWP have been originally introduced in order to explain anomalous acoustic and thermal properties of amorphous materials by the socalled two-level systems, the existence of which is due to tunneling in DWP with appropriate parameters. The photophysical model is based on spectral shifts (matrix-shift-variations) caused by phonon-induced crossing of the barriers which can occur in all DWP if the phonon frequency is high enough.

© 1991 Optical Society of America