Simple Evaluation Procedure of Nonlinear Absorptivity in Glass Welding using USLP with High-Pulse Repetition Rates

A simple non-dimensional equation has been derived to evaluate nonlinear absorptivity in simplified non-dimensional form, if the cross-sectional area of the molten region is experimentally given in internal melting of glass by ultrashort laser pulses at high pulse repetition rates. Based on a series of experiment using different glasses including D263, Foturan and fused silica in wide variety of experimental conditions, it is shown that the evaluated nonlinear absorptivity has an excellent correlation with the results obtained by previously reported simulation model.