The manual shows a deep commonality of oscillatory and wave processes, regardless of their nature. Electromechanical analogy is widely used. The reader's attention is primarily drawn to the physical meaning, clarity and applications important for understanding the essence of the studied phenomena and their theoretical models. The propagation of optical waves in metal and dielectric waveguides is discussed in detail. A separate chapter is devoted to the influence of nonlinear effects, which consider the phenomena of self-modulation, self-focusing of light beams, generation of optical harmonics, formation and propagation of optical solitons. Problems, solution of which contributes to fixation of studied material, are given.