Anti-reflection coatings for epsilon-near-zero materials

Epsilon-near-zero (ENZ) materials have attracted much interest within the photonics community due to various novel light-matter interactions that can occur in ENZ regime. These display a large impedance mismatch between material and free space, making it difficult couple light into medium at normal incidence. In this article, we demonstrate enhanced coupling an metamaterial stack be achieved via design fabrication of anti-reflection coatings, which are simple fabricate e-beam evaporation. The coating fabricated has been optimized not only minimize reflection but also aims maximize transmission — these designs applicable e.g. beam shaping applications. We achieve enhancement 20% through our over 150 nm range minimization 50% 200 range.