Abstract
Upper and lower limits for the actual microbending loss of single-mode fibers with arbitrary refractive index profile are given. These limits strongly depend on the shape of the actual fundamental mode field. It is shown that the minimum splice loss due to a small offset for a given microbending loss is obtained for a fiber with a Gaussian fundamental mode field. Fibers with similar splice loss and non-Gaussian fundamental mode fields like multiple-clad single-mode fibers will exhibit significantly larger microbending losses.