This publication covers the basic principles of operation of optical devices designed to measure current, voltage, magnetic field and other parameters in powerful electrophysical devices. Here are presented the physical foundations of methods for measuring their optical and electrical characteristics obtained using calculations and experiments. The book is intended for students and graduate students of physical and technical specialties, as well as for scientists and engineers engaged in the problems of physics of high energy densities, and will be useful in developing an edition of experiments in the intensively developing field of modern physics.