Self-induced polarization changes in birefringent optical fibers

Abstract

Exact solutions are presented for the intensity-dependent polarization state of a light wave in a birefringent optical fiber. The theory takes into account both the linear polarization evolution and the nonlinear ellipse rotation. It is shown that, contrary to current belief, self-induced polarization changes are possible even with equal excitation of the fiber’s principal axes. The theory is applicable to the operation of recently demonstrated fiber-optic logic gates, pulse shapers, and intensity discriminators.