Resistance of a corner cube reflector with a dielectric antireflection coating to the space environment

Abstract

Subject of study. The negative effect of corpuscular radiation of outer space on the optical properties of a corner cube reflector with a multilayer dielectric coating is studied. Aim. The feasibility of applying a bilayer antireflection dielectric coating for radiation with a wavelength of 532 nm on the input face of a corner cube reflector operated in a high-orbit spacecraft is investigated. Method. Electron–proton irradiation simulating the effect of hot magnetospheric plasma on corner cube reflectors with and without antireflection coatings was carried out using a simulation stand. Because the corner cube reflector is made of KU-1 radiation-resistant quartz glass, special attention was devoted to the formation of electrostatic discharges that accompany the irradiation of the samples. Main results. The induced optical density of the coating of the input face of corner reflectors caused by magnetospheric plasma particles increased with the distance from the geometric center of the aperture of the input face to the metal frame. This can be explained by the fact that discharges with the maximum intensity were observed in the vicinity of the frame, resulting in the destruction of the near-surface layers of the irradiated samples. It has been experimentally established that the antireflection effect of a bilayer coating, which comprises HfO2 (thickness of approximately 25 nm) and SiO2 (thickness of approximately 100 nm), leveled with increasing irradiation dose. Practical significance. The results demonstrate that the use of the investigated bilayer antireflection coating is advisable in optical systems of a high-orbit spacecraft with an active lifetime not exceeding 6 years or under conditions of lower dose load.