Determination of thin film optical parameters from photometric measurements: an algebraic solution for the (T,R_f,R_b) method

A new method of analysis for the simultaneous determination of the optical constants and the thickness of thin films is proposed. It requires measurements under normal incidence of the transmission and of the reflections from both sides of a thin film deposited on a nonabsorbing sbstrate. An algebraic inversion technique is developed involving a numerical interpolation procedure in the last step. There are no missing solutions. The physical solution can be isolated by a comparison with some film thickness estimates or by measurements in a wavelength range.