Light scattering model for the determination of fiber location in silicone coatings

A ray trace model is developed which describes the intensity and phase characteristics of a forward-scattered pattern generated by transversely illuminating a silicone-coated fused-silica fiber with a laser beam. The dominant characteristic of this pattern is a region of interference fringes which result from the interference of rays traveling through the fibers and the coating and rays traveling through the coating only. The location of the fringe region and the fringe period depends on fiber and coating parameters and the fiber eccentricity within the coating. The parameter sensitivities are examined, and the model results compared to experimentally measured'characteristics of the light scattering pattern.