The back-scattered pattern produced by a plane-polarized beam incident normally on a large uncladded optical fiber can be used to determine the refractive index and the radius of the fiber. The geometricoptics method is used to analyze the pattern. A new procedure to find the radius of the fiber is proposed.The procedure can make use of nearly the whole of the back-scattered pattern, without need to measure exactly the positions of all of the individual fringes. Special attention is given to the limits of accuracy.
John W. Y. Lit, "Radius of uncladded optical fiber from back-scattered radiation pattern," J. Opt. Soc. Am. 65, 1311-1315 (1975)