Optical imaging describes the behavior of visible, ultraviolet, and infrared radiation used in imaging techniques based on optical principles. Reflection, refraction, interference, scattering, transmission, polarization and/or luminescence/fluorescence processes are involved in the optical study of different materials, organic, inorganic, natural or synthetic. In this book, the authors discuss optical image analysis and determination of dispersed multi-phase flow for simulation and control; optical imaging applications for the study of cultural heritage artifacts; atomic and magnetic force microscopy of semiconductor and semimagnetic nanocrystals; imaging, spectroscopy and sensing with single and coupled metallic nanoparticles; methods for suppressing random and nonrandom noise in fluorescence imaging; and optical coherence tomography.