Attenuation of waveguide modes of thin films: separation of contributions of absorption and surface scattering of the light

Analytical solution for the problem on separation of contributions of the material effects of absorption and surface scattering of the light in the attenuation coefficients of TE polarization modes is obtained under the assumption of a good localization of the energy of waveguide modes in a thin film and mean square deviations and the autocorrelation intervals of rough boundaries of film are small than the wavelength of the radiation. Based on this solve the algorithm of reconstruction of the imaginary part of the complex refractive index for the film is formulated. This algorithm uses of the real parts of the propagation constants and attenuation coefficients for the two TE modes of film, that are measured by means the waveguide spectroscopy. Effectiveness of the approach is confirmed by calculation of the diffraction fields arising at the propagation of waveguide modes along the film with rough boundaries.