Phase-Contrast Images

Abstract

We see phase contrast any time we have more than one beam contributing to the image. In fact, whenever we say ``fringes,'' we are essentially referring to a phase-contrast phenomenon. Although we often distinguish phase and diffraction contrast, this distinction is generally artificial. For example, in Chapters 24 and 25, we will examine thickness fringes and stackingfault fringes; both types of contrast result from interference of waves so both are phasecontrast images although we usually think of them as two-beam, diffraction-contrast images.