Modeling of the absorption spectra of films for a finding optical constants
Achieving the maximum potential range, effective contrast transmission and obtaining images characterized by a higher signal-to-noise ratio is achieved in vision systems with optical antennas, which are characterized by a transparency coefficient close to the maximum. Often such systems use coherent illumination and infrared sources to obtain an image. The technical implementation of optical systems designed to work in systems of this type requires the development of antireflection and protective coatings of interference type. The quality of their synthesis is based on solving the problem of finding optical constants, especially for films for which there are dissipative energy losses in the considered part of the spectrum. The search for film constants using the spectrophotometric measurement method is complicated by the ambiguity of the procedure for analyzing spectrophotometric spectra. In this paper, a technique is used to minimize the errors of such an analysis. It is based on the correction of film spectra taking into account dissipative losses characterized by an absorption coefficient. Correction of the spectra is carried out by using an absorbing film model. The influence of the model shape on the accuracy of correction of absorption spectra is calculated. This technique allowed us to obtain the frequency dependences of the optical constants of BaMgFx 4 films at wavelengths from 1.3 to 27 microns.
Authors: E. N. Kotlikov, V. M. Andreev, N. P. Lavrovskaya, G. V. Tereshchenko
Direction: Physics
Keywords: optical constants, absorption, spectrum, modeling technique
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