Detailed studies have been carried out for various dopants on the coupling length (L) of the two fundamental modes of orthogonal polarization to preserve a state of linear polarization over long lengths. Theoretical calculations indicate that L < 2.3 mm is essential to maintain good polarization. Two fundamental single polarization fibers, the elliptical-core and elliptical-clad fibers, have been prepared by CVD. Experimental results show that a B2O3 dopant yields a substantially large anisotropic birefringence than does GeO2 and P2O5. The effects of noncircularity and normalized frequency of the fiber on L have been experimentally considered.
© 1983 Optical Society of America
T. Katsuyama, H. Matsumura, and T. Suganuma, "Propagation characteristics of single polarization fibers," Appl. Opt. 22, 1748-1753 (1983)