The Aquila nkd scanning spectrophotometer (for surface analysis) combines a well known technique with sophisticated computer analysis and dedicated design. Even if you already have a spectrometer , you will still need an nkd. In effect they achieve the same goal, but there are huge advantages for spectrophotometers over ellipsometer, cost and ease of use being the main examples. Also available articles on spectrophotometry vs ellipsometry (pdf format). The MiniSIMS is used in research and quality control for the chemical analysis of solid surfaces using Secondary Ion Mass spectrometry (SIMS).