This book reflects the substantial progress made in the area of optical fibers and provides for the first time a systematic description of linear and non-linear fiber devices, including fiber couplers, splices, connectors, multiplexers, switches, and modulators. Primarily aimed at advanced undergraduate and graduate students in optics, optoelectronics, applied physics, and electrical and electronic engineering, this book serves as a valuable reference for scientists and engineers working in optoelectronics and related fields in industry and academic. Topics include coupling, devices based on coupling effect with non-polarized light, devices using polarized light, devices based on nonlinearities, and devices based on rare earth doped fibers.