Polarisation fluctuation on the backward Rayleigh scattered signal measured by the POTDR (polarisation optical time domain reflectometer) has been investigated by means of the power spectrum. As a result, the spectrum is sharply peaked at the Fourier frequency of 8.3 − 106 Hz determined by the polarisation beat length of 12 m due to the difference in phase velocities between the orthogonal eHE11 and oHE11 modes. The value is in good agreement with the analysis.
- Optical fibres
- Rayleigh scattering