Collinear acousto-optical interaction of twofold-degenerated modes of bi-refractive optical fiber-optical waveguides

Acousto-optical transformation of linearly polarized ($LP_{0m}$) modes of fiber-optic waveguides placed into external electrical field and made from the material in which it is possible to achieve transverse electro-optical effect is investigated. The possibility of simultaneous acousto- and electro-optical polarization-independent light modulation by the longitudinal acoustic mode $L_{01}$ of a cylindrical waveguide is shown. The possibility of the application of the acousto-optical transformation of such a mode transformation with indicated properties for construction of tunable acousto-optical filters is stated.