Speckle, a granular structure appearing in images and diffraction patterns produced by objects that are rough on the scale of an optical wavelength, is a ubiquitous phenomenon, appearing in optics, acoustics, microwaves, and other fields. This book provides comprehensive coverage of this subject, including both the underlying statistical theory and the applications of this phenomenon. This second edition offers improvements of several topics and addition of significant amounts of new material, including discussion of: generalized random walks, speckle in the eye, polarization speckle (and the statistics of the Stokes parameters in a speckle pattern), the effects of angle and wavelength changes on speckle, the statistics of speckle from “smooth” surfaces, and a spectrometer based on speckle. Many new references are also included. As with the first edition, a multitude of areas of application are covered.