Rayleigh Scattering Process

Rayleigh scattering is the dominant intrinsic loss mechanism in the low- absorption window between the ultraviolet and infrared absorption tails. It results from in inhomogeneities of a random nature occurring on a small scale compared with the wavelength of the light. These in inhomogeneities manifest themselves as refractive index fluctuations and arise from density and compositional variations which are frozen into the glass lattice on cooling. The compositional variations may be reduced by improved fabrication, but the index fluctuations caused by the freezing in of density in inhomogeneities are fundamental and cannot be avoided. Read More