Abstract

We report the first application of optically detected stimulated echoes to the measurement of trap to trap migration rates in mixed molecular crystals. The stimulated echo (1) can be thought of as a 2-pulse echo in which the 180° refocussing pulse is split into two 90° pulses. This has the effect of storing local field information along the longitudinal or population difference axis in the rotating frame. This information is then "read-out" in the form of an echo by the third 90° pulse. Since the ability to recall or "stimulate" the echo at the later time depends on how well the local field alignment is preserved during the long waiting time T, the stimulated echo intensity reflects changes in local fields and can be used to probe trap to trap energy migration.

© 1984 Optical Society of America