Introduction. Basic Theory. Theoretical Techniques. Antireflection Coatings. Neutral Mirrors and Beam Splitters. Multilayer High-Reflectance Coatings. Edge Filters and Notch Filters. Band-Pass Filters. Tilted Dielectric Coatings. More on Tilted Coatings. Other Topics: From Rugate Filters to Photonic Crystals. Color in Optical Coatings. Production Methods. Material Properties. Composite, Birefringent and Metamaterials. Some Coating Properties Important in Systems. Specification of Filters and Coatings. Characteristics of Thin-Film Dielectric Materials.