Abstract:
PURPOSE: To shift a minimum attenuation point to a minimum dispersion area without requiring a complicated production work by reducing a heterogenous area in materials of an optical fiber. CONSTITUTION: The optical fiber is oscillated with a superaudible frequency, which brings about rearrangement of atoms to a lower energy state, to reduce the heterogenous area in materials of the optical fiber. This external stress is, for example, oscillation with the super-audible frequency applied for several minutes and is realized with a simple device, namely, a furnace where the fiber is heated up to a desired temperature and an ultrasonic generator which oscillates the fiber. Thus, attenuation due to Rayleigh scattering is reduced by relaxation induced in the molecular structure.