Rapid optical sampling of relaxation-phenomena employing two time-correlated picosecond pulsetrains

Two flashlamp-pumped, mode-locked and optically coupled dye lasers produce trains of picosecond pulses with definite, but variable time correlation. One pulsetrain is used to bleach the sample, while the other probes the decay of its transient transmission. Relaxation times between 15 ps and 1 ns can be monitored by one simultaneous activation of the two lasers.