Effect of gas atmosphere and pressure on 351 nm laser-induced damage threshold of fused silica

S∶1, 1∶1 and R∶1 laser damage tests for fused silica were performed under different gas atmosphere (air, O2, N2) and pressures (10-3~105 Pa) with 351 nm Nd:YLF laser. The results show that laser-induced damage threshold(LIDT) via 1∶1 and S∶1 tests are almost the same in different gas atmosphere and pressures. The LIDT via R∶1 tests are more liable to pressure than gas atmosphere. The R∶1 threshold of fused silica under pressures lower than 103 Pa decrease by 28%~41% compared with that at 105 Pa. Under equal pressure but different gas atmosphere the R∶1 threshold has less than 10% deviation, which is within the measurement error. The multi-pulse irradiation resistant property for different gas atmosphere and pressures were also studied under irradiation of half of the damage thresho