Evidence of Superexciplex in Dye Molecules

Abstract

The excited state behavior of dye molecules under intense pulsed laser excitation appears to differ from that under low-power cw Xenon lamp excitation. In the latter case molecules absorb photons (from the lamp), go to the excited state and produce normal fluorescence. This is a one photon–one molecule process. But in the former case, two excited dye molecules combine together to form `superexciplex' and produce fluorescence and also amplified spontaneous emission (ASE) under intense, sharp, laser pulse excitation. This paper gives sufficient evidence verifying the existence of this new molecular species.