Beam deviation in the polarizing elements is identified as a significant source of error in existing ellipsometer alignment procedures. A high precision alignment procedure that eliminates these errors is described. This procedure is less time consuming than previous methods, and its accuracy is comparable to the limit of resolution of the ellipsometer (typically 0.01-0.005°). A further advantage of this procedure is that it provides a precise method for the alignment of specimens and lasers with the ellipsometer.
J. R. Zeidler, R. B. Kohles, and N. M. Bashara, "High Precision Alignment Procedure for an Ellipsometer," Appl. Opt. 13, 1115-1120 (1974)