This book contains a good literature survey of various mathematical models and routing & wavelengths assignment algorithms in WDM optical networks. Some of the new algorithms for optimization of blocking probability have aslo been covered. This book is good for researchers who are working on optical networks and advancements in fiber optics communication. Mathematical models covered in this book are simple and easy to implement. A good number of routing and wavelength assignment algorithms have also been covered in this book which can be used to reduce blocking probability of the optical network. This book can be very helpful to the research scholars.