The communications industry is at the onset of new expansion of WDM technology necessary to meet the new demand for bandwidth. This is the second of a four reference books that will cover this technology comprehensively with all of the major topics covered by a separate volumes - i.e. active components, passive components, systems and networks. This book is the first which covers all key passive optical components required for current and next generation optical communication systems. World-renowned authors, who are pioneers in their research area, have written the chapters in their area of expertise. The book highlights not only the principle of operation and characteristics of the passive optical components, but also provides an in-depth account of the state-of-the-art system applications. - Helps the reader to choose the right device for a given system application. - Provides the reader with insight and understanding for key passive optical components frequently being / to be used in the optical communication systems, essential building blocks of today's/next generation fiber optic networks. - Allows engineers working in different optical communication areas(i.e. from system to component), to understand the principle and mechanics of each key component they deal with for optical system design. - Covers Planar lightwave circuit (PLC) based router, different optical switches technologies (based on MEMS, thermo-optic, and electro-optic) and different optical amplifier technologies (based on semiconductor optical amplifier, EDFA ,and raman amplifier). - Highlights the operating principle of each component, system applications, and also future opportunities.