Introduction to Optical Thin Films

In this introductory chapter, we discuss the origins of interference phenomena. We then consider the manner in which these effects are combined to produce practical interference filters. In this book, the terms filters and coatings are used interchangeably, and mean any type of optical coating deposited on a substrate. For example, an antireflection coating is a filter as is a narrow bandpass coating design. The coating may consist of one or more layers, the optical thickness of which is on the order of a wavelength of light. We confine our discussion to those coatings that are used in optical devices and for optical purposes. We do not consider nonoptical uses for coatings such as decorative, protective, and electronic.