We examine the nonlinear interaction between the linearly polarized modes on a few-mode elliptical-core optical fiber. Three modes are involved in this process: the fundamental (LP<sub>01</sub>) mode and the two second-order symmetry modes, LP<sub>11</sub> (even) and LP<sub>11</sub> (odd), which have slightly different propagation constants. In practical situations the large δβ = β<sub>01</sub> – β<sub>11</sub> (β is the propagation constant) precludes any significant coupling between the fundamental and either of the LP<sub>11</sub> modes; however, coupling between the two LP<sub>11</sub> symmetry modes may occur for sufficient pump intensities. Exact and approximate analytic expressions are given.
© 1992 Optical Society of America
S. J. Garth and C. Pask, "Nonlinear effects in elliptical-core few-mode optical fibers," J. Opt. Soc. Am. B 9, 243-250 (1992)