Optimal single-band normal-incidence antireflection coatings

TLDR

The study proposes explanations for the observed semiperiodic clustering of layers in optimal single‑band antireflection coatings. The authors provide mathematical and computational evidence that such optimal coatings exist, demonstrate efficient synthesis and refinement methods to find them, and present examples and performance graphs showing semiperiodic layer clustering across various substrates and wavelength ranges.

Abstract

Mathematical and computational evidence that strongly suggests that optimal solutions exist to single-band, normal-incidence antireflection coating problems is presented. It is shown that efficient synthesis and refinement techniques can quickly and accurately find such solutions. Several visible and infrared antireflection coating examples are presented to support this claim. Graphs that show the expected optimal performance for different representative substrates, refractive-index ratios, wavelength ranges, and overall optical thickness combinations are given. Typical designs exhibit a pronounced semiperiodic clustering of layers, which has also been observed in the past. Explanations of this phenomenon are proposed.