Over the past two decades, the demand of Rare Earth (RE) doped optical fibres has increased enormously for their applications in the field of optical amplifier, fibre laser and sensors. In this context, there is a growing need to improve the fibre performance and produce the fibres more reproducibly. The Modified Chemical Vapor Deposition (MCVD) process coupled with solution doping method is commonly employed to produce the preform and fibres due to greater flexibility of the process. However, control of RE concentration and the doping non-uniformity still continue to be the major problems and are responsible for high cost of the fibres compared to standard SMF. This book, provides description of individual process steps, inherent problems associated with each step, remedies to different problems, quantitative correlation of different process parameters with fibre properties and modeling work to improve the process repeatability to large extent. A large number of figures, tables, graphs related to experiments carried out along with updated reference list makes this book invaluable for engineers, scientists, and students working with specialty optical fibre