LASER-INDUCED SURFACE-PLASMON DESORPTION OF DYE MOLECULES FROM ALUMINUM FILMS

Rhodamine B molecules were desorbed without fragmentation from the surface of an Al film by surface-plasmon-induced desorption. Surface plasmons were excited in the Al film by the second harmonic of a Nd:YAG laser in an attenuated-total-reflection (ATR) geometry. The desorbed neutrals were ionized by a XeCl excimer laser and detected by a time-of-flight mass spectrometer. The desorption yields of both Al and rhodamine B showed a dependence with incidence angle which peaked at the plasmon resonance angle. The thresholds for desorption of Al and rhodamine B occur at the same laser fluence. Two models are proposed to explain these observations.