Anomalous spectral modulation of the mode-field diameter of single-mode fibers

摘要

The determination of the mode-field diameter of single-mode fibers may be strongly affected by bending insensitive cladding and coating modes. The presence of these modes is visible in the measurement trace of the cut-off wavelength. The resulting anomalous spectral modulation of the mode-field diameter can be eliminated by immersion of the coated fiber in an index matching liquid or sufficient bending of the fiber.