Triple-clad single-mode fibers for dispersion shifting

A design procedure for triple-clad dispersion-shifted single-mode fibers is developed. Following this procedure, fibers are identified which have low dopant concentrations in the core compared to those of the previous dispersion-shifted fiber designs, a second-mode cutoff wavelength close to the operating wavelength, zero dispersion at 1550 nm, a small bending loss at 1550 nm (for a bend radius of 3.75 cm), and a spot size that is large enough not to compromise the splice loss. A significant advantage of these fibers is that low-dispersion is available over a wide wavelength band about the wavelength of zero dispersion