The book addresses the natural link between electromagnetics and optics. The electromagnetic origin phenomena is sought through a dual approach to optics which is based on the wave equation and ray theory. A review of the underlying principles, as well as mechanisms of wave/ray interactions with matter are presented first. An examination of guided propagation of light through various dielectric waveguides follows. Aspects of resonant light propagation, such as Gaussian beams, resonators and lasers, are treated next. The basic theory of light processing by optical elements is presented in the fourth part which covers Fourier optics, the scalar theory of diffraction and holography. The book further refers to miscellaneous topics, such as optical radiation, remote sensing and nonlinear phenomena.