Variations of parameters Tolerance considerations, as illustrated in Figure

Single Abstract Single-mode fibers of pure silica core and F-rioped clads exhibiting a low dispersion over a wide wavelength range are discussed and numerical results of some propagation charac­ teristics of dispersion-compensated multiclad fibers are presented. In computations, the very accurate numerical methods and extended precision arithmetic were used. The calcula­ tions include the propagation constant, and the dispersion coefficient versus a wavelength, cut-off frequencies of the first mode, a power and field distribution of the fundamental HE,, mode, the spot size. Tolerance of the geometry of the fiber and concentrations of the F-do- pants in pure silica are analysed showing numerically what is an influence of them on a dispersion characteristic. Some results to be discussed are directly applicable to the desig­ ning of a truly single-mode F-doped silica fiber.