Improvement of the mode quality in large mode area (LMA) fibres

We used the offset launch and the near field imaging technique to analyse the modal content of large mode area (LMA) fibres in different launch conditions. The coiling technique was applied to suppress higher order mode contents in order to estimate the modal power distribution and to verify the loss factor for the single modes. Based on this analysis, an optimised coiling for LMA fibres will be developed, to suppress the higher order mode contents while maintaining the highest possible fundamental mode content.