Thickness measurement for volume holograms by analysis of first-order diffraction.
We present a method for measuring the thickness of volume holograms by analyzing the variations of the diffraction efficiency as a function of angle of incidence. This method can be justified theoretically within the Born approximation for gratings with small modulation. But we prove experimentally that the method can work surprisingly well even for strongly modulated volume holograms. The principle of the method consists of the determination of angles of incidence for which the first-order diffraction efficiency takes its extreme (maxima and minima) values: these angles are related to the thickness of the grating.
Harthong
J
J
Medjahed
A
A