Fundamentals of Optical Waveguides gives a complete theoretical basis of optical fibers and planar lightwave circuits. Fundamental analytical waveguide theories are introduced and various numerical methods are are presented. Recent topics on planar lightwave circuit (PLC) devices are described including operational principles of arrayed-waveguide grating multiplexers (AWGs) and their applications. Readers will acquire a thorough understanding of optical fibers and waveguides as well as capabilities of designing and simulating novel optical devices.