Enhanced ArF laser absorption in a collagen target under ablative conditions

The time-resolved transmission of collagen targets during ArF excimer laser ablation has been measured. The transmitted excimer pulse measurements demonstrate enhanced media attenuation that is a nonlinear function of incident laser fluence. Forward scattering of the transmitted pulse has been assessed to be a negligible contributor to the observed phenomena. Results of pump/probe interrogation of the ablation site indicate that the onset of enhanced attenuation occurs on the time course of the ablating laser pulse and persists for times on the order of hundreds of microseconds.