Over the last few decades, optical coating technologies have been becoming progressively more complex. Optics control light in a manner to make a product useful, and coatings do a great job in that by modifying how light is transmitted, absorbed, and reflected to make the product more efficient and functional. Optical coatings are made up of several thin film layers, creating an interference effect. How the coating works depends on variables like the number of layers, the thickness of each coating layer, and the different refractive indices of each layer.
