Effective cutoff wavelength of the LP11mode in single-mode fiber cables

The effective cutoff wavelength of the LP
11
mode is investigated for nylon-coated step-index type single-mode fibers stranded in a cable. It is found from the pulse propagation experiments that the single-mode operation is effectively attained in the two-mode region up to the
V
-value of 3.0. It is numerically estimated that splice loss, bending loss, and absorption loss due to the OH-ion in cladding are reduced by choosing the operating
V
-value as large as 3.0.