ISSN 0021-3454 (print version)
ISSN 2500-0381 (online version)
Menu

12
Issue
vol 60 / DECEMBER, 2017
Article

DOI 10.17586/0021-3454-2016-59-10-860-866

UDC 681.7.064.454

EXTENDING ENLIGHTENMENT AREA OF SMALL-SIZE OPTICAL ELEMENT BY COATING WITH A SPECIFIED THICKNESS DISTRIBUTION

L. A. Gubanova
ITMO University, 197101, Saint-Petersburg, Russian federation; Professor


H. L. Thang
ITMO University, Saint Petersburg, 197101, Russian Federation; student


Read the full article 

Abstract. Anti-reflection coating formed by layers with specified distribution of geometric thickness on the surface of optical elements of a very small radius (2—12 mm), is investigated. Distribution of the energy reflection coefficient along the optical element surface is studied. It is revealed that for the given coating structure, the relative size of the enlightenment area defined as the ratio of the radius for the optical element surface where the reflection is less than a certain value (ρ) to the element radius (r), is independent of the curvature radius of the optical element made of homogeneous material. The relative size ρ/r depends of the refractive index of the optical element material and of the antireflection coating design. For the reflection coefficient of less than 1 %, it is possible to obtain the maximum enlightenment area of relative size ρ/r = 80 % with single layer coating, ρ/r = 82 % with double-layer coating, and ρ/r = 81.5 % with three-layer coating. It is shown that multiplying the number of coating layers allows for insignificant extension of the enlightenment area, but makes the coating applicable in a wider range of wavelengths. It is concluded that for extending the enlightenment area, formation of coating layers with a specified distribution of geometric thickness is required.
Keywords: anti-reflective coating, area of enlightenment, small-radius optical detail

References:
  1. Herzig H.P. Micro-Optics: Elements, Systems and Applications, CRC Press, 1997, 600 р.
  2. Rancourt J.D. Optical Thin Films: User Handbook, Bellingham, SPIE, 1996, 304 р.
  3. Kuzin A.A., Zablotskiy A.V., Baturin A.S., Lapshin D.A., Melent'ev P.N., Balykin V.I. Nanosistemi, Nanomateriali, Nanotehnologii, 2009, no. 1(7), pp. 163–168. (in Russ.)
  4. Khryachkov V.V., Fedosov Yu.N., Davydov A.I., Shumilov V.G., Fed'ko R.V. Endoskopiya. Bazovyy kurs lektsiy (Endoscopy. Basic Course of Lectures), Moscow, 2012. 160 p. (in Russ.)
  5. Khatsevich T.N., Mikhaylov I.O. Endoskopy (Endoscopes), Novosibirsk, 2002, 196 p. (in Russ.)
  6. Macleod H.A. Thin-Film Optical Filters, 4th ed., Boca Raton, FL, CRC Press, 2010, 800 p.
  7. Baumeister P.W. Optical Coating Technology, SPIE Press monograph, 2004, V. PM137, 840 p.
  8. Grunwald R., Mischke H., Rehak W. Applied Optics, 1999, no. 19 (38), pp. 4117–4124.
  9. Hermans K., Hamidi S.Z., Spoelstra A.B., Bastiaansen C.W.M., Broer D.J. Applied Optics, 2008, no. 35 (47), pp. 6512–6517. DOI: 10.1364/AO.47.006512.
  10. Tomofuji T., Okada N., Hiraki S., Murakami A., Nagatsuka J. Optical Interference Coatings, OSA Technical Digest Series, 2001, art. no. MD2.
  11. Karasev N.N., Nuzhin A.V., Starovoytov S.F., Putilin E.S., Bol'shanin A.F., Mashekhin V.T., Slobodyanyuk A.A. Opticheskie tekhnologii (Optical Technology), St. Petersburg, 2006, 98 p. (in Russ.)
  12. Kotlikov E.N., Varfolomeev G.A., Lavrovskaya N.P., Tropin A.N., Khonineva E.V. Proektirovanie, izgotovlenie i issledovanie interferentsionnykh pokrytiy (Design, Production and Research of Interferential Coverings), St. Petersburg, 2009. (in Russ.)
  13. Gubanova L.A., Khoang Long Tkhan', Do Tay Tan. Scientific and Technical Journal of Information Technologies, Mechanics and Optics, 2015, no. (215), pp. 234–240. (in Russ.)
  14. Ershov A.V., Mashin A.I. Mnogosloynye opticheskie pokrytiya. Proektirovanie, materialy, osobennosti tekhnologii polucheniya metodom elektronnoluchevogo ispareniya (Multilayered optical coverings. Design, materials, features of technology of receiving by method of electron beam evaporation), Nizhniy Novgorod, 2006, 99 p. (in Russ.)
  15. Putilin E.S. Opticheskie pokrytiya (Optical Coating), St. Petersburg, 2010, 227 p. (in Russ.)