Abstract

Over 30 years ago, Pohlack¹ proposed a method of synthesis based on polynomial curve fitting. After proving that 1/T (or R/T) of a sequence of layers with equal optical thickness had to be a polynomial of the type P=A₀cos^2mφ +A₁cos^2m−2φ+A₂cos^2m−4 φ +. . . , with φ =(πλ)/(2λ₀) and m= total number of layers, he proceeded to calculate the coefficients of the polynomial as a function of the refractive indices of the individual layers. Equating these equations with the desired coefficients, he could arrive at a system of equations of sufficient number to calculate the refractive indices. Although the theory had a large impact on the theoretical understanding of multilayer interference coatings, the equations were too complex to be of much practical value.

© 1988 Optical Society of America