UV to IR high-efficiency antireflective surface modification of freeform and cylindrical lenses for space platform optical instrumentation

Randomly distributed anti-reflective nanostructures were fabricated on both surfaces of cylindrical lenses and freeform optical surfaces, using a plasma assisted reactive-ion etching technique. Spectral transmission of an average 98% was measured across the range 340-800 nm. Mid-band full-angle directional scatter measurements show a difference of six orders-of-magnitude in transmission intensity between specular and off-specular angles. Measurements before and after the etching process show little to no wavefront distortion for the cylindrical lenses. As the nanostructures are etched into the optical surface their thermal and mechanical shock resilience is high, as verified by our prior work on fused silica windows.