Asymptotic effective cutoff condition in single-mode optical fibers

Recently some experimental investigations have shown that the effective cutoff wavelength of the LP11mode in a single-mode optical fiber decreases with increased distance from the optical source. In this paper such a phenomenon is theoretically investigated confirming that asymptotically the effective cutoff wavelength reaches a minimum value, dependent on few key parameters. Furthermore, attention is focused onto the excess attenuation which characterizes this behavior, leading to a remarkable penalty in the design of the optical link. The wavelength dependence of this parameter seems to be very useful in order to improve the cable manufacturing process.