The app calculates the reflectance for two-layer anti-reflection at normal incidence. It shows the reflectance versus wavelength, which depends on the refractive index and film of thickness.

The calculator program is following electromagnetic theory and transfer matrix theory: Frank J. Pedrotti, Leno S.Pedrotti, by Frank J.Pedrotti, Leno S.Pedrotti., [Introduction to Optics (2nd ed)], Prentice-Hall, Upper Saddle River Publishers, N.J. 391-396, (1993).