Structural modifications in fused silica due to laser-damage-induced shock compression

High power laser pulses can produce damage in high quality fused silica optics that can lead to its eventual obscuration and failure. Current models suggest the initiation of a plasma detonation due to absorbing initiators and defects, leading to the formation of shock waves. Recent experiments have found a densified layer at the bottom of damage sites, as evidence of the laser-damage model. We have studied the propagation of shock waves through fused silica using molecular dynamics. These simulations show drastic modifications in the structure and topology of the network, in agreement with experimental observations.