Multipulse degradation of fused silica surfaces at 351 nm

摘要

We investigate the multipulse degradation of fused silica surfaces exposed at 351 nm for up to 10~9 pulses at pulse fluences greater than 10 J/cm~2. In vacuum, the transmission loss increases as a function of the number of shots at low pulse intensity. However, as the pulse intensity increases, the transmission loss decreases and is not measureable above a certain intensity. Transmission loss is highest when measured at shorter wavelengths, and decreases towards the IR. Absorption is the primary mechanism that leads to transmission loss and is from photo-reduction of the silica surface.