Interference fringes of equal inclination at large angles of incidence

Захаров Ю.Н., Чалкова Н.В. Интерференционные полосы равного наклона при больших углах падения // Оптический журнал. 2009. Т. 76. № 11. С. 75–78.

Zakharov Yu.N., Chalkova N.V. Interference fringes of equal inclination at large angles of incidence [in Russian] // Opticheskii Zhurnal. 2009. V. 76. № 11. P. 75–78.

Yu. N. Zakharov and N. V. Chalkova, "Interference fringes of equal inclination at large angles of incidence," Journal of Optical Technology. 76 (11), 730-732 (2009). https://doi.org/10.1364/JOT.76.000730

Interference in thin films, including the formation of fringes of equal inclination, is usually considered for small angles of incidence of light. However, it is necessary in a number of cases to use large angles of incidence of the rays, when it is illicit to replace the sine of an angle by its argument. This paper presents an exact calculation of the parameters of an interference pattern formed at large angles. A nonmonotonic dependence of the distance between the interference fringes on the angle of incidence is detected in this case. Moreover, an expression that connects the distance between the fringes with the angle of incidence, the wavelength of the light source being used, and the thickness of the sample is obtained in this paper that is not limited by the traditional approximation and more accurately describes the fringes of equal inclination. An experimental verification confirms the results.

The research was partially supported by the grant of RFBR No. 08-04-97-109 and grant of the Ministry of Science and Education of the Russian Federation No. 2.1.1/6223.