Large-area omnidirectional antireflection coating on low-index materials

Large-area subwavelength dielectric hexagonal lattices of cylindrical pillars on quartz substrates that provide high optical transmittance at all angles of incidence under different polarizations of light, and are fabricated using low-cost patterning techniques, are demonstrated and analyzed. Transmittance > 85 % for angles of incidence in excess of 70[degrees] is demonstrated at visible and near-infrared wavelengths, and the structures employed are shown to be superior at visible wavelengths to tapered "moth eye" surfaces for practically achievable dimensions. Detailed analytical calculations and numerical simulations elucidating the impact of feature size, height, periodicity, and refractive index are presented.