This book combines the most relevant aspects of waveguide theory with the study of detailed waveguiding technologies. The first three chapters examine the theoretical foundations and bases of planar optical waveguides, as well as critical optical properties such as birefringence and nonlinear optical phenomena. The next several chapters focus on contemporary waveguiding technologies that include photonic devices and telecommunications. The book concludes with discussions on additional technological applications, including biomedical optical waveguides and the potential of neutron waveguides.