Review of optical fibers-introduction and applications in fiber lasers

The optical fibers which are considered as waveguides can be applied to light transmission applications. The core part of the optical fiber is surrounded by a glass or plastic layer called cladding which is characterized by the refractive index that is lower compared to the core refractive index. The total internal reflection phenomena are necessary for the fine confinements of the light within the waveguide. Basically, optical fibers can be categorized based on the structure, modes number, refractive index profile, dispersion, signal processing ability, and polarization. In this report, we focus on the first three common types of optical fibers. As a common application of the fibers, these can be used in fiber lasers to create and amplify a narrow intense beam of coherent and monochromatic light. Fabrication of optical fiber involves three stages such as the preform formation. Modified chemical vapor deposition (MCVD) method is a known technique, which can be used to fabricate the optical fibers. Optical fiber sensors are well known for wide range applications in optics and photonics. As a sensing application, optical biosensors can be made based on the refractive index changes that used widely for detection of biomolecules in their natural forms.