Selective damage of coloration centers inhomogeneously distributed in skin tissue under nanosecond near-IR laser pulses

Abstract

The results are presented on the study of the damage of melanin granules contained in ex-vivo animal skin specimens under a series of single Nd:glass laser pulses of nanosecond duration, with intensity I ~ 10 8 W/cm 2 . The mechanism responsible for tissue damage at the given conditions is shown to be a selective photodisruption occurring due to preferential energy absorption by endogenic skin pigment. For such a complicated multicomponent structure as biotissue comprising substructures inhomogeneously distributed in the bulk of it and differing in physical and chemical properties, such a parameter as volume energy density becomes a decisive one for tissue damage. When its magnitude reaches the damage threshold value within the absorption loci it breaks whereas the surrounding tissue remains undisturbed.