Highly Effective Index-Matching Antireflective Structures for Polymer Optics

Optical polymers are attractive for lightweight and cost-effectiverefractive optical components, yet they reflect part of the incidentlight. Traditional vacuum-deposited antireflective films purely adhereto polymers and suffer from mechanical stresses due to the differencein the thermal expansion coefficients. Alternatively, reflection canbe reduced by moth-eye structures; yet, their efficiency stronglydepends on their index-matching with the optical substrate, whichhas not been demonstrated so far. Here, we introduce a new approachto engineering highly effective antireflective structures on the surfaceof the optical polymer, with an unprecedented ability to reduce thesurface reflection from 5 to 0.1%. The structures were produced byhigh-throughput nanoimprint lithography, and their superior opticalperformance was achieved due to the precise matching of their indexto that of the underlying substrate. We further applied these structureson different polymers and showed that their antireflective effectcorrelates with index-matching. We demonstrated that these structurescould be applied on flat surfaces and curved lenses and produce highsurface hydrophobicity. Overall, our work paves the way to an efficientand scalable antireflective solution for polymer optics.