Open AccessAn optical examination of thin films. I.—The optical constants of mercury
Author(s) -
Leif Tronstad,
C. G. P. Feachem
Publication year - 1934
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1934.0085
Subject(s) - refractive index , polishing , materials science , mercury (programming language) , optics , attenuation coefficient , thin film , cleavage (geology) , analytical chemistry (journal) , chemistry , composite material , optoelectronics , physics , nanotechnology , organic chemistry , fracture (geology) , computer science , programming language
Drude originally suggested that the properties of films on both absorbing and non-absorbing substrates could be studied by an optical method, since the reflecting properties of a surface are modified by the presence of a film. This method has in part been used by various workers, with some success. For liquid surfaces, or for smooth surfaces of solids, such as are obtained by cleavage or after suitable polishing, it is possible to measure “the relative phase retardation,” Δ, and “the ratio of the reflection coefficients,” tan ψ, which define the reflecting properties. From the values of Δ and ψ for a clean surface, the refractive index,n , and the absorption coefficient,k , characteristic of the material can be found from the approximate equationsn = sinϕ tanϕ cos 2ψ/(1 + cos Δ sin 2ψ), (1.1)k = sin Δ tan 2ψ, (2.1) whereϕ is the angle of incidence.