There are three types of modes- guided modes, radiation modes and leaky modes. The modes which are guided by optic fibers by means of multiple total internal reflections are termed as guided modes. Radiation modes lower the power output. These modes are generated when angle of incidence is less than the critical angle. Another possible reason for radiation modes is the traveling of rays through cladding material. Leaky modes which are very unstable propagate in the fiber with the variation of their amplitudes. Major part of the mode is lost in the beginning itself. Since only a small fraction reaches the other end, leaky modes contribute significantly to power loss in optic fibers. These modes have important role while designing optical fibers for different applications especially in fiber optic communication.
No comments:
Post a Comment