Formation of light with controlled rotation of the polarisation plane by superposing linearly polarised waves

A method is proposed for generating linearly polarised light, whose polarisation plane rotates at a given frequency. The method is based on the double passage of the light through an acousto-optic modulator made of an anisotropic crystal. An experimental prototype based on a paratellurite crystal is fabricated, with the help of which rotation of linearly polarised light of a He – Ne laser (λ = 0.63 mm) is obtained with the frequency controlled by the frequency of sound.