ABSTRACT
Metals have complex refractive indices and therefore exhibit significantly different optical properties than dielectrics. Thin film coatings are ubiquitous on all optical components such as lenses, mirrors, cameras, and windows. Besides antireflection and high-reflection filters, there are many other types of optical filters, such as long-pass, short-pass, bandpass, and line-pass filters. Ultrathin transparent metal films can be used in applications where electrical conductivity, optical transparency, and reflectivity are simultaneously desired, such as in displays and smart mirrors. Compared to metal surfaces, dielectric reflectors can provide better control of the reflection bandwidth. They can also produce lower absorption, which is important in high power laser applications. Numerical refinement will be necessary to optimize the design across all wavelengths, but providing the computer with a good starting point makes it possible to achieve the objectives of the design with the fewest number of thin film layers.
