Nonlinear absorption of thin Al2O3 films at 193 nm

Abstract

Absorption of thin Al2O3 films was measured at 193 nn with an ArF-laser calorimeter. In addition to the expected high linear absorption coefficient, we found, for the first time to our knowledge, that two-photon absorption and transient color-center formation are nonnegligible loss channels in thin films at 193 nm. The nonlinear absorption coefficient is of the order of several times 10(-4) cm/W. (C) 2000 Optical Society of America. OCIS codes: 310.6860, 310.1620, 260.7190.