Rotations of elliptic vortex beams in media with and without anisotropy

Abstract

We introduce the anisotropy into the evolutions of the vortex, and discuss three different kinds of dynamics: circular shaped vortex in linear anisotropic media, elliptic shaped vortex in linear isotropic media, and elliptic shaped vortex in linear anisotropic media. The evolutionary processes dramatically depend on both the anisotropic parameter δM of the media and the initial aspect ratio ρ0 of the elliptic vortex. Under the critical condition , the elliptic vortex will not rotate, and keeps its aspect ratio invariant during the evolutions. Generally, when , the dynamics of the elliptic vortex can be divided into three stages: nonuniform process, rotational process and uniform process. In the nonuniform and the uniform processes of the vortex, the positions of the outer elliptic peaks and the inner elliptic holes do not change in spite of the nonzero energy flow. Also, the energy distributions become nonuniform in the former process, and uniform in the latter process. In the rotational process, the outer peaks and the inner holes can both rotate, but with the opposite rotational directions.