Influence of mismatch between fibers on nonlinear distortion of signals in optical communication lines

An investigation was made of nonlinear distortions of a signal by a mismatched connector in a fiber-optic communication line, originating from interference between the fiber modes. An experimental investigation established that the nonlinear distortions could be greater than the earlier theoretical estimates because of a strong deviation of the emission wavelength resulting from modulation of the semiconductor laser power. It was found that the distortion amplitude depended strongly on the matching between a laser and a fiber.