Reactive fibers are fibers that have one or more laser active dopants in the fiber core. In most cases, they are rare earth-doped fibers with doped contaminants such as ytterbium, erbium, or thulium. Thanks to these dopants, they can be used as laser gain media and can also be used to implement fiber amplifiers. Rarely, reactive fibers are made from transition metal ions.
Reactive fibers are usually made of some glass, in most cases from fused silica (quartz fibers), however, there are also some reactive single crystal fibers.
In addition to being able to amplify light (typically with high gain efficiency, high power conversion efficiency, and high output beam quality), optical fibers typically exhibit high propagation losses, which are negligible due to the fact that only short fiber lengths are typically required. In most cases, they are single-mode or low-mode fibers, and sometimes large-mode fibers or polarization-holding fibers.
Laser amplification is not the only possible physical mechanism for gaining gain in an optical fiber: stimulated Raman scattering (SRS) and Kerr nonlinearity of the fiber can also be used for this purpose. In this case, one can consider the fiber optics as active fibers because it amplifies the light.
Be the first to comment