Rapid lifetime testing of fused silica for DUV laser applications

Abstract Lifetime testing of fused silica's absorption degradation upon 193 nm is shortened by enhancing the two-photon absorption (TPA) induced generation of E′ and NBOH defect centers per laser pulse. Increasing the irradiation fluence from typical marathon test values H For a UV grade fused silica sample (type III) the end of absorption degradation is found after about 1.2 * 107 laser pulses. Absorption measurements between 3 and 25 mJ/cm2 before and after lifetime testing reveal that the laser induced absorption change decreases with decreasing fluence. The experimental results are in good agreement with a real marathon test at a fixed fluence.