Light scattering in polaritons in a biaxial crystal near the binormal

The features of the frequency-angle spectrum of scattering in polaritons in a biaxial crystal, which form when the wave vector of the polariton is oriented near the binormal, are examined. When the scattering plane deviates from the plane containing the binormal the scattering branch is disintegrated along the wave vector; the corresponding distribution in intensity in this case may be explained by the change in the magnitude of the convolution of the quadratic susceptibility with unit vectors of polarization of three interacting waves with rotation of the unit vector of polariton polarization.