Theoretical calculations of crosstalk and time delay in identical FBG array in PM fiber

The spectral shadowing, multiple reflections and polarization crosstalk in an identical FBG array in PM fiber were theoretically studied. For a PM fiber FBG array (PMF-FBG array) with FBG peak reflectivity of -30 dB, grating spacing of 2 m and total fiber length of 2000 m, the reflection power of the PMF-FBG changed from -30.0 dB to -36.9 dB at the end of the array because of the spectral shadowing and the multiple reflections. Equations for the signal time delay of the PMF-FBG array were given. Higher birefringence in the PM fiber will result in a longer time delay.