ARF-EXCIMER LASER-INDUCED SECONDARY RADIATION IN PHOTOABLATION OF BIOLOGICAL TISSUE

Secondary radiation, emitted during and after the irradiation of corne al, dermal, and dental tissue by an ArF-excimer laser (193 nm), was qu alitatively and quantitatively characterized. Emission of secondary ra diation was found in the range of 200-800 nm. The intensity of seconda ry radiation in the range of 200-315 nm (UVC and UVB) is approximately 20% of the total intensity at high laser fluences (>2 J/cm2) , and ap proximately 50% at moderate laser fluences (<500 mJ/cm2); 10 muJ/cm2 i n the UVC and UVB were measured at the sample surface, at fluences (<1 J/cm2) which are of relevance for clinical procedures on soft tissues . In dental tissue processing, very high fluences (>5 J/cm2) are requi red. As a consequence, laser-induced plasma formation can be observed. Secondary radiation can be used as a visible guide for selective remo val of carious altered tissue. The data we have found might be of assi stance in estimating potential hazards for future mutagenic studies in the field. (C) 1994 Wiley-Liss, Inc.