Chapter 2 discusses the basics of wave optics and briefly introduces the reader into the wave propagation in an optical medium, which simplifies the study of the material presented in following chapters. Such terms as optical medium and its theoretical description are described shortly. The Maxwell’s equations are written and principal conception of plane wave propagation is discussed. Then, optical wave behavior in a dielectric medium is considered by means of general solution of the wave equation and such crucial parameters as polarization, refractive index and group velocity are considered.