DOI: 10.17586/2226-1494-2015-15-2-234-240


L. A. Gubanova, H. L. Thang, T. D. Tan

Read the full article 
Article in Russian

For citation: Gubanova L.A., Hoang Long Thanh, Do Tai Tan. Study of reflection coefficient distribution for anti-reflection coatings on small-radius optical parts. Scientific and Technical Journal of Information Technologies, Mechanics and Optics, 2015, vol.15, no. 2, pp. 234–240.

The paper deals with findings for the energy reflection coefficient distribution of anti- reflection coating along the surface of optical elements with a very small radius (2-12 mm). The factors influencing the magnitude of the surface area of the optical element, in which the energy reflection coefficient is constant, were detected. The main principles for theoretical models that describe the spectral characteristics of the multilayer interference coatings were used to achieve these objectives. The relative size of the enlightenment area is defined as the ratio of the radius for the optical element surface, where the reflection is less than a certain value, to its radius (ρ/r). The result of research is the following: this size is constant for a different value of the curvature radius for the optical element made of the same material. Its value is determined by the refractive index of material (nm), from which the optical element was made, and the design of antireflection coatings. For single-layer coatings this value is ρ/r = 0.5 when nm = 1.51; and ρ/r = 0.73 when nm = 1.75; for two-layer coatings ρ/r = 0.35 when nm = 1.51 and ρ/r = 0.41 when nm = 1.75. It is shown that with increasing of the material refractive index for the substrate size, the area of minimum reflection coefficient is increased. The paper considers a single-layer, two-layer, three-layer and five-layer structures of antireflection coatings. The findings give the possibility to conclude that equal thickness coverings formed on the optical element surface with a small radius make no equal reflection from the entire surface, and distribution of the layer thickness needs to be looked for, providing a uniform radiation reflection at all points of
the spherical surface.

Keywords: anti-reflection coating, small-radius optical detail, area of constant reflection coefficient.

Acknowledgements. This work was partially financially supported by the Government of the Russian Federation (Grant 074- U01).

1. Kuzin A.A., Zabolotskiy A.V., Baturin A.S., Lapshin D.A., Melent'ev P.N., Balykin V.I. Method for production of microlenses less than 50 nm in diameter for nanolithography using atomic projective optics.
Nanosistemi, Nanomateriali, Nanotehnologii, 2009, vol. 7, no. 1, pp. 163–168.
2. Khryachkov V.V., Fedosov Yu.N., Davydov A.I., Shumilov V.G., Fed'ko R.V. Endoskopiya. Bazovyi Kurs Lektsii [Endoscopy. Base Course of Lectures]. Moscow, GEOTAR-Media, 2012, 160 p.
3. Khatsevich T.N., Mikhailov I.O. Endoskopy [Endoscopes]. Novosibirsk, SGGA Publ., 2002, 196 p.
4. Micro-Optics: Elements, Systems and Applications. Ed. H.P. Herzig. London, Taylor & Francis, 1997, 600 p.
5. Macleod H.A. Thin-Film Optical Filters. 4th ed. Boca Raton, CRC Press, 2010, 800 p.
6. Putilin E.S. Opticheskie Pokrytiya [Optical Coatings]. St. Petersburg, SPbSU ITMO Publ., 2010, 227 p.
7. Baumeister P.W. Optical Coating Technology. SPIE Press monograph, 2004, vol. PM137, 840 p.
8. Grunwald R., Mischke H., Rehak W. Microlens formation by thin-film deposition with mesh-shaped masks. Applied Optics, 1999, vol. 38, no. 19, pp. 4117–4124.
9. Hermans K., Hamidi S.Z., Spoelstra A.B., Bastiaansen C.W.M., Broer D.J. Rapid, direct fabrication of antireflection-coated microlens arrays by photoembossing. Applied Optics, 2008, vol. 47, no. 35, pp. 6512– 6517. doi: 10.1364/AO.47.006512
10. Tomofuji T., Okada N., Hiraki S., Murakami A., Nagatsuka J. A new coating technique for lenses which have steep curved surface. Optical Interference Coatings, OSA Technical Digest Series, 2001, art. MD2.
11. Karasev N.N., Nuzhin A.V., Starovoitov S.F., Putilin E.S., Bol'shanin A.F., Mashekhin V.T., Slobodyanyuk A.A. Opticheskie Tekhnologii [Optical Technologies]. St. Petersburg, SPbSU ITMO Publ., 2006, 98 p.
12. Ershov A.V., Mashin A.I. Mnogosloinye Opticheskie Pokrytiya. Proektirovanie, Materialy, Osobennosti Tekhnologii Polucheniya Metodom Elektronnoluchevogo Ispareniya [Multilayer Optical Coatings. Design, Materials, Production Technology Features by Electron Beam Evaporation]. Nizhnii Novgorod, NNGU
Publ., 2006, 99 p.
13. Kotlikov E.N., Varfolomeev G.A., Lavrovskaya N.P., Tropin A.N., Khonineva E.V. Proektirovanie, Iizgotovlenie i Issledovanie Interferentsionnykh Pokrytii [Design, Manufacture and Research of Interference Coatings]. St. Petersburg, GUAP Publ., 2009, 188 p.
14. Spravochnik Tekhnologa-Optika [Handbook of Optics Technologist]. Ed. M.A. Okatov. 2nd ed. St. Petersburg, Politekhnika Publ., 2004, 679 p.
15. Tai Do T., Gubanova L.A., Putilin E.S., Van Khoa P. Five-layer quarter-wave anti reflective coatings for the IR region. Journal of Optical Technology (A Translation of Opticheskii Zhurnal), 2014, vol. 81, no. 10, pp. 72–76. doi: 10.1364/JOT.81.000612
Copyright 2001-2017 ©
Scientific and Technical Journal
of Information Technologies, Mechanics and Optics.
All rights reserved.