Laser desorption studies using laser-induced fluorescence of large aromatic molecules

Pulsed laser desorption of non-volatile organic dye molecules paraterphenyl and tetra-t-butyl-p-quinquephenyl (QUI) was studied using gas phase ultraviolet laser induced fluorescence, following heating of a steel substrate by a pulsed 1.06-mu m Nd:YAG laser. The fluorescence signal intensity is linear in concentration up to at least 30 monolayers and shows infrared power threshold behavior, as expected for evaporation, at similar to 0.2 J/cm(2). Similar signal levels were also observed in air, with 532-nm heating, and using other metallic or dark black surfaces.