Comparison between techniques for measuring the LP11-mode cutoff wavelength in monomode fibres

The LP11-mode cutoff wavelength ¿c of a monomode fibre can be obtained by measuring changes in microbending loss or mode field width. These two methods have been compared and it was found that the presence of microbending in the latter technique resulted in a discrepancy of between 0.04 and 0.12 ¿m in the measurement of ¿c.