Mitigation of the birefringence dispersion on the polarization coupling measurement in a long-distance high-birefringence fiber

Due to the birefringence dispersion, the polarization coupling parameter measurement in high-birefringence fiber decreases obviously with the fiber length, especially for long-distance fibers. In this paper, two methods for mitigating the birefringence dispersion in a long-distance fiber are proposed. The first method is a spectral-domain measurement method. The experimental setup and results are described in detail. The other method is a time-domain numerical dispersion compensation algorithm to amend the coupling strength calculation equation. It is based on the fact that the interferogram envelope area is constant even with the existence of birefringence dispersion. The experimental result shows that the time-domain algorithm has high accuracy, and the absolute deviation is less than 1%. The two methods are validated to mitigate the birefringence dispersion in the long-distance high-birefringence fiber effectively. (paper)