Abstract: This research will study the ability of directional coupler realization on the ground of double refraction in anisotropic spiral stowed fiber at room temperature, the importance of using the features of anisotropic media to minimize the attenuation and dispersion in the transmitted signals in the fiber optic system of transfer which caused by the power exchange between waves and the possibility to get calculation results for specific cases. And try to determine the half-length of the beat region ξ₁ for a certain composition of the 1 spiral single mode optical fibers depending on the parameters of the spiral to construct spiral single mode optical fibers based on photo elasticity. Also in this research we will try to define specific parameters which can be taken as a basis for directional couplers design to uniformly separate the power of the optical signal and to obtain the condition of uniform power distribution between the main waves (HE₁₁^e and HE₁₁^o).