Anisotropy of optical properties of hexagonal boron nitride films

Thin films of hexagonal boron nitride with a thickness of several monatomic layers were prepared by splitting bulk samples in an ultrasonic bath. The spectra of transmission, reflection, and photoluminescence from such films were studied. The spectral dependences of the linear and circular polarization of the light transmitted through the sample were measured. Scanning electron microscopy examination showed the homogeneity of the samples obtained. However, the study of the Stokes parameters of the light transmitted through the sample made it possible to establish the presence of hidden anisotropy of the optical properties of these films.