Ablation of liquid benzene by pulsed ultraviolet (248 or 308 nm) laser radiation

Irradiation of liquid benzene with laser pulses (248 nm, ≈ 20 ns fwhm) at fluences > 0.2 J/cm2 caused ablation of the liquid surface. The shock wave which was transmitted through the liquid when the ablated material left the surface was detected by a piezoelectric transducer. When the liquid surface was constrained by a quartz plate, the threshold for ablation increased ( > 0.4 J/cm2),the intensity of the shock wave was amplified by an order of magnitude, and carbon was formed abundantly as a product. Ablation was observed with 308 nm laser pulses also even though there is no corresponding one-photon absorption. Ablation of benzene is attributed to the absorption of more than 2 photons per molecule. © 1988.