Synthesis of Multiple Antireflection Films over a Prescribed Frequency Band

TLDR: In this article, the synthesis of multilayer dielectric films as antireflection coatings over any specified frequency band has not been attempted before, and the design procedure (synthesis) described herein leads to the best possible antireslection films, but demands precisely controlled materials with certain refractive indices.

Abstract: The synthesis (as opposed to analysis) of multilayer dielectric films as antireflection coatings over any specified frequency band has not been attempted before. The similarity with transmission lines, which can be synthesized as multisection quarter-wave transformers to minimize reflection over any prescribed frequency band, is utilized by applying recently developed synthesis procedures for quarter-wave transformers to the synthesis of multiple antireflection films. [ See O. S. Heavens , Optical Properties of Thin Solid Films ( Academic Press, Inc., New York, 1955); and P. J. Leurgans , J. Opt. Soc. Am.41, 714 ( 1951).] A brief review of network synthesis is given, leading up to the synthesis of quarter-wave transformers and multilayer films. Numerical tables are presented in this paper from which antireflection coatings of up to four layers can be designed by interpolation. The design procedure (synthesis) described herein leads to the best possible antireflection films, but demands precisely controlled materials with certain refractive indices. It is hoped that this paper will help to promote the development of such materials, and will encourage opticists to try experimentally for the optimum performances possible in theory.