ArF laser induced pulse absorption in fused silica (type III): Modeling the fluence and repetition rate dependence

At 193 mn, weak stationary bulk absorption coefficients alpha(stat) in standard and experimental grade fused silica (type 111) are measured in dependence on the laser fluence H and repetition rate f. The samples show non-linear increases alpha(stat) (H) for 0.2 <= H <= 5 mJ cm(-2) pulse(-1) (f = const.) and) alpha(stat)(f) for 100 <= f <= 1000 Hz (H = const.). An absorption model, focussing on ArF laser induced E' center generation and annealing, and the associated rate equations are applied to simulate the experimental data quantitatively. From the simulations, material parameters like the 2-photon absorption (TPA) coefficient, the E' center absorption cross section sigma(E') and the hydrogen related E' annealing rate are calculated. TPA coefficients values of 9.7 . 10(-9) cm/W (standard grade material) and 1.4 . 10(-8) cm/W (experimental grade material), E' center cross sections of 4.5 . 10-(18) and 3.6 . 10-18 cm(2) and hydrogen annealing rates of 1.5 s(-1) (standard grade) and 3.4 s(-1) (experimental grade) are found. (C) 2009 Elsevier B.V. All rights reserved.