Optical coatings and metamaterials

Abstract

An optical surface rarely presents the idea optical behavior desired for the system in which it is employed. Modifying these properties is the task of an optical coating and virtually all optical surfaces in all optical systems carry such treatments. Most often the coating consists of a number of thin layers exhibiting interference effects that yield a suitable performance. Coating performance is constrained by the normal properties of interference. Such behavior could benefit considerably from the use of metamaterials and particularly those exhibiting a negative index of refraction. Unfortunately such true negative index still appears elusive. Negative refraction has been convincingly demonstrated particularly for p-polarization and this is certainly useful in a number of applications but metamaterials have not so far yielded the complete set of properties representing the true negative index that could transform the field of optical coating