Dynamics of dislocations and disclinations of the field of a few-order optical fiber: I. Creation and annihilation of C ± disclinations

It is shown experimentally and theoretically that the interconversion dynamics of the field of the LP₁₁ mode combination of a few-mode optical fiber is determined by the interaction of circularly polarized pure edge C ⁺ and C ⁻ disclinations. The C ⁺ and C ⁻ disclinations correspond to characteristics of the field for which the right-or left-circularly polarized electric field goes to zero. During propagation the uniformly linear-polarized dislocations D _y break down into four C ⁺ disclinations travelling in opposite senses. When each pair of C ⁻ and C ⁺ disclinations meet they annihilate each other and form linear polarization. The field of the linearly polarized disclinations thus created sums up out of phase into the original field and forms a uniformly linearly polarized field with D _x dislocations. Pis’ma Zh. Tekh. Fiz. 23, 20–27 (January 26, 1997)