Broadband Antireflection Coverglass for CubeSats

Abstract

A CubeSat is a type of miniaturized and modular satellite designed for space research or technology demonstration. By filling the unused capacity of major launch vehicles, CubeSats significantly lower the cost of entry to space. To reduce the energy loss at the solar panel coverglass on CubeSats, we investigated the potential of the biomimetic moth-eye antireflection (MEAR) techniques which feature a gradient refractive index (GRIN). A novel fabrication process combining nanosphere lithography, reactive ion etching and dry oxidation for patterning glass with moth-eye structures was reported that allows for the production of well-defined nanopillars with tunable sidewall profiles. The thermal annealing treatment of colloidal particles was first introduced for making MEAR structures for which partial deformation of nanospheres was achieved. The broadband and omni-directional anti-reflective performance of fabricated glasses was experimentally demonstrated by using spectrophotometer and ellipsometer. A 2% and 10% decrease of reflectance throughout the measured spectral range was observed at normal incidence and high incident angles respectively.