Evaluation of the optical constants and thicknesses of weakly absorbing non-uniform thin films

Abstract Formulae are deduced and evaluation procedures, both graphical and by computer, are derived for the evaluation of the optical constant n ( v and k ( v ), the mean thickness d and the relative thickness variation Δd d = γ of transparent and weakly absorbing wedge-shaped thin films. The films may be free or supported on thick transparent substrates of known refractive index n s ( v ). The evaluation procedure uses only transmission data, i.e. the spectral transmission curves and their envelope curves which together define sets of tangency points used in the calculations.