Thin film refractive index determination

[sounouhid]

Hi every one ,
I want to find the refractive index of a thin film using it's reflectance and transmittance spectrum
is there a way to do that ?
thank you for advance

 

[Charles Link]

Normally, you already know the index of refraction of the thin film material, and the thickness of the film can be computed by observing the spacing of the peaks in the transmission vs. wavelength spectrum due to the Fabry-Perot effect. If I remember correctly $\Delta \lambda= \lambda^2/(2nd)$.

 

[sounouhid]

Thank you
but my task is to find both the refractive index and the thickness of the film from these two measurements