Pulse distortion in optical fibers with transverse offset splices

A method for calculating the pulse distortion in a spliced multimode optical fiber vs transverse misalignment is presented. Measurements on two graded-index and one step-index fibers are shown. In graded-index fibers both theory and experiment show a rapid decrease of the rms pulse width for large offsets. For smaller offsets some discrepancies are observed. These are remedied to some extent by considering unequal mode excitation conditions. Different lengths of the two spliced sections are investigated as well. In the step-index case the experiments show no variation in the rms pulse width as predicted by the theory.