Abstract: The method for switching optical radiations having orthogonal polarization includes the steps of inserting a linearly polarized wave into the input of a birefringent object (an optical waveguide or crystal) and feeding a small polarized small optical signal is also orthogonally into the object. The polarization vector of the linearly polarized pumping signal or of the optical signal is directed along an optical axis of the birefringent object or at a small angle to the optical axis. The pumping intensity is selected to be higher than the threshold value I.sub.p, which is proportional to a difference between the effective refractive indices of orthogonally polarized radiations and inversely proportional to a cubic nonlinear coefficient of the object. In addition, the intensity of the optical signal radiation is varied from zero to a maximum value of <0.1 I.sub.p.