A mathematical model is derived for the focusing method which relates refractive-index and deflection function errors to errors in the measured light intensity. The model predicts that refractive-index measurement noise increases linearly from zero at the outside diameter of the fiber to a maximum value at the center of the core. Measurement errors for the focusing method determined by experiment are in close agreement with predictions obtained using the theoretical model.
© 1985 Optical Society of America
D. H. Irving, T. W. Whitbread, and C. J. E. Phillips, "Error analysis of the focusing method for optical fiber and preform refractive-index profile measurement," Appl. Opt. 24, 3128-3133 (1985)