The refractive index measurements of RF magnetron sputtered ZnO thin film on sapphire

Measurements were made of the refractive index of an RF magnetron sputtered ZnO thin film on sapphire. We compare the experimental results to theory when TE and TM guided waves propagate in the plane at an arbitrary angle with respect to the
c
axis when the
c
axis lies in the plane of the film. Care also should be taken when one uses
m
-line spectroscopy to determine the refractive index of a film.