An optical measurement system, including a reference ellipsometer and a non-contact
optical measurement device, evaluates a sample having at least a partially known
composition. The reference ellipsometer includes a light generator to generate
a beam of quasi-monochromatic light of known wavelength and polarization, directed
at a non-normal angle of incidence to interact with the sample. An analyzer creates
interference between S and P polarized components of the reflected beam, the intensity
of which is measured by a detector. A processor determines the polarization state
using the detected intensity, and determines an optical property of the sample
based upon the determined polarization state, the known wavelength, and the composition.
The processor calibrates the optical measurement device, used to measure an optical
parameter of the sample, by comparing the measured optical parameter from the optical
measurement device to the determined optical property from the reference ellipsometer.
