FIELD: measuring.
SUBSTANCE: invention relates to methods for determining optical properties of thin-film objects of subwavelength thickness. Method for determining the dielectric constant of the material of a thin-layer object in the terahertz range involves depositing an object in the form of a homogeneous layer of known subwavelength thickness on a flat substrate, generating a beam of surface plasmon polaritons (SPP) on it by terahertz radiation, determination of refraction index and absorption index of SPP before application of the analysed layer on the substrate and if available, calculation of dielectric permeability of the material of the object based on the measurement results. At that, the substrate is selected as conducting and containing a homogeneous coating layer of a non-absorbing dielectric with a thickness at which the SPP propagation length is maximum, the radiation is selected as monochromatic, refraction index of SPP is estimated using a Michelson plasmon-polariton interferometer assembled on a substrate. Analysed layer is selected mechanically strong and is applied only on that part of the substrate, on which the movable mirror of the interferometer moves.
EFFECT: high accuracy of the method for determining dielectric permeability of the layer material in the THz range.
1 cl, 2 dwg
