Study of the first stages of laser-induced contamination

Abstract

A vacuum chamber was designed to study the risk of laser-induced contamination (LIC) on optical payloads integrated on spaceflight missions. In this context, tests were performed with a nanosecond pulsed laser at 355 nm on fused silica substrates under toluene exposure with multiple laser irradiation. Specific experimental procedures are described in order to obtain repeatable results. Finally, series of tests were performed to investigate the onset of the LIC deposition process and its evolution over time. A slight antireflective effect is consistently observed at the onset of the deposition process. We suggest that this is an indication that the LIC deposition process in our experimental conditions starts with a nucleation layer consisting of small dense islands of deposit.