Abstract. Peculiarities of synthesis of broadband coatings for separation of achromatic light in the spectral range of 1,5—25 microns to be used in Fourier spectrophotometers of intermediate and far IR, are considered. Methods for the synthesis of multilayer coatings and the stability analysis of coatings are developed. The films are created from materials based on Ge and ZnS, the optical constants of Ge and ZnS films are determined in the spectral range from spectrophotometerс data with the use of correction of optical spectra for absorption. Two synthesized multilayer coatings with 4 and 5 layers are tested. The both coatings meet the requirements and are recommended for the use as coatings for separation of achromatic light for Fourier spectrophotometers of intermediate and far IR. Comparison of the coatings in the required spectral range demonstrate a higher resistance of the 4-layer coating to errors in the layers, has the smaller criterion of stability and feature quality, and is easy to manufacture. intermediate and far IR.

Keywords: synthesis, analysis, thin film, achromatic coatings, optimization, stability, optical constants

References:

1. Bell R.J. Introductory Fourier Transform Spectroscopy, Academic Press, 1972.
2. http://www.infraspek.ru/produktsiya/. (in Russ.)
3. Kotlikov E.N., Novikova Yu.A. Optics and spectroscopy, 2014, no. 3(117), pp. 381–385.
4. Kotlikov E.N., Kuznetcov Yu.N., Lavrovskaya N.P, Tropin A.N. Nauchnoe Priborostroenie (Scientific Instrumentation), 2008, no. 3(18), pp. 32–36. (in Russ.)
5. Kotlikov E.N., Novikova Yu.A., Tropin A.N. Proektirovanie i izgotovlenie interferentsionnykh pokrytiy (Design and Production of Interferential Coverings), St. Petersburg, 2016, 288 р. (in Russ.)
6. Kotlikov E.N., Ivanov V.А., Prokashev V.N., Tropin A.N. Optics and spectroscopy,2010, no. 6(108), pp. 827–830. (in Russ.)
7. Poelman D., Smet P.F. J. Phys. D: Appl. Phys., 2003, no. 36, pp. 1850–1857.
8. Kotlikov E.N., Novikova Yu.A., Yurkovets E.Yu. Scientific session of the Saint-Petersburg State University of Aerospace Instrumentation, 2016, рр. 253–257. (in Russ.)
9. Andrievskiy B.V., Vakhulovich V.F., Kurlyak V.Yu., Romanyuk N.A. Optics and spectroscopy, 1988, no. 1(65), pp. 136–140. (in Russ.)
10. Kotlikov E.N., Novikova Yu.A. Optics and spectroscopy, 2016, no. 5(120), pp. 815-817.
11. Kotlikov E., Iurkovetc E. Journal of Physics: Conference Series, 2016, no. 737, pp. 012042 doi:10.1088/1742-6596/737/1/012042/.
12. Kotlikov E., Iurkovetc E. Journal of Physics: Conf. Series: Journal of Physics: Conf. Series, 2017, no. 857, pp. 012023. DOI: 10.1088/1742-6596/857/1/012023/.
13. Kuznetsov S.M., Okatov M.A., ed., Spravochnik tekhnologa-optika (Reference Book by the Technologist-Optician), Leningrad, 1983, 414 р. (in Russ.)
14. Kotlikov E.N., Iurkovetc E.Yu. Journal of optical technology, 2018, no. 1(85), pp. 1–6. (in Russ.)
15. Kotlikov E.N., Novikova Yu.A., Kovalenko I.I. Informatsionno-upravliaiushchie sistemy (Information and Control Systems), 2015, no. 1(68), pp. 15–20. (in Russ.)
16. Kotlikov E.N., Novikova Yu.A. Informatsionno-upravliaiushchie sistemy (Information and Control Systems), 2013, no. 1(62), pp. 41–46. (in Russ.)