The vector coupled-mode analysis considering the exact HE11 modes is applied to two single-mode coupled optical fiber cores, including the strongly guiding fibers. The accuracy of the conventional coupled-mode theory and the recently formulated new theory as applied to the two-core system is examined. Array modes of different polarization states are considered. It is shown that the full-wave coupled-mode calculations behave well in predicting the array-mode propagation constants beyond the weakly guiding regime and that the simpler conventional theory can provide satisfactory results when applied in the vectorial form.
© 1989 Optical Society of America
Horng Shou Huang and Hung-Chun Chang, "Vector coupled-mode analysis of coupling between two identical optical fiber cores," Opt. Lett. 14, 90-92 (1989)