Damage modeling and statistical analysis of optics damage performance in MJ-class laser systems

Abstract

Modeling the lifetime of a fused silica optic is described for a multiple beam, MJ-class laser system. This entails combining optic processing data along with laser shot data to account for complete history of optic processing and shot exposure. Integrating with online inspection data allows for the construction of a performance metric to describe how an optic performs with respect to the model. This methodology helps to validate the damage model as well as allows strategic planning and identifying potential hidden parameters that are affecting the optic's performance.

Analysis of the beam-pointing stability in the high power laser system

“…This laser system is ideally suited for a wide variety of high-energy-density scientific experiments, including laser-induced damage mechanism for UV optics research [20][21][22], stimulated Brillouin scattering (SBS) [23][24][25][26][27] and stimulated Raman scattering (SRS) [28,29]. To obtain one beam with an aperture of 60-mm-diameter, the whole size of the laser system is designed to be about 7 m length, 2 m height and 1.5 m width.…”

Optics damage modeling and analysis at the National Ignition Facility

“…Our methodology consists of developing a dataset that uses various existing databases to capture the essence of the full shot history, as well as the processing and installation history, of all wedge focus lens (WFL) optics installed on NIF [10]. The aim of creating this dataset is to be able to evaluate the performance of each optic given everything we know of its processing and exposure.…”

“…This dataset starts by using NIF's optics work-order database to establish the lifecycle of an optic, which is then used to collect the shot history and inspection data from other databases. The result condenses a large array of dissimilar datasets into a concise dataset that is easily managed and analyzed; we refer to this dataset as the optics performance table (OPT) [10]. For this study, we focus on NIF wedge focus lenses from 2010-2013.…”

Understanding the effect of HF-based wet shallow etching on optical performance of reactive-ion-etched fused silica optics

“…In high-power fusion-class laser facilities, the service life of fused silica optics is known to be severely limited by their surfaces, as laser-induced damage (LID) initiation and damage growth lead to unacceptable obscuration or even catastrophic failure of the optics. 1,2 The LID of the fused silica surface, which typically scales with the laser uence, results from the presence of extrinsic damage precursors located on the surface or within the subsurface layer of the optics. 3 Photoactive impurities (e.g., ceria) in the polishing redeposition layer 4,5 as well as electric defects associated with a fractured surface, 3,6,7 which are capable of strongly absorbing sub-band-gap light and spawning optical damage, have been identied as main laser-damage precursors.…”