ABSTRACT
At the time this book is written, we celebrate 40 years since Corning manufactured the first optical fiber having optical losses lower than 20 dB/km, thus opening the road for commercial applications. Although the technological revolution that followed was initially focused on telecommunication applications, in time, optical-fiber research and engineering broadened its scope, covering today a much larger number of domains: material processing, sensing, signal processing, etc. As a result, over time, the number of fiber structures, materials and manufacturing technologies has increased exponentially. In spite of this diversity, the vast majority of commercially available optical fibers are not that different from the onemade by Corning 40 years ago, that is: a waveguide structure created inside silica. There are many reasons why this has happened: silica is an abundant material, its processing is a mature technology and, very importantly, it accepts a large number of dopants that can alter its properties.
