Applications of the normal-incidence rotating-sample ellipsometer to high- and low-spatial-frequency gratings.

The normal-incidence rotating-sample ellipsometer is an instrument that can be used to characterize grating surfaces from the measured ratio ρof complex reflection coefficients r(y)/r(x) of light polarized perpendicular and parallel to the grating groove direction. Experimental results at different wavelengths for different gratings with spatial frequencies from 150 to 5880 grooves/mm are presented. The groove depth of the 5880-grooves/mm gold-coated grating can be estimated from the measured ρ and rigorous grating theory.