A: Basics of Optics

Abstract

Many powerful methods of experimental mechanics are based on optical phenomena. Approaches in this class include, for example, photoelasticity, speckle interferometry, laser Doppler, and moiré interferometry. Typically, these techniques are noncontact, relatively noninvasive, and they yield data over the entire field of interest. Informed application of these techniques requires understanding of basic optics. The purpose of this chapter is to provide the necessary background knowledge in wave optics. The exposition begins with the nature and description of light and its interactions with materials, then progresses to the first cornerstone of optical methods, interference, and its manifestation in classical interferometric applications. The second cornerstone, diffraction at an aperture, is then treated along with its application in optical spatial filtering. Geometrical optics is not discussed. Where possible, reliance is on physical reasoning in place of mathematical manipulation. The main goals are utility, clarity, brevity, and accuracy.