A vectorial modulation transfer function approach of diffraction patterns o
bservable around Brewster's incidence is proposed. The good agreement betwe
en experimental results and vectorial model will allow the correlation of r
efractive index measurement accuracy with the average magnitude of surface
defects. Consequences in the metrology of refractive index gradients will t
hen be briefly discussed. (C) 1999 Elsevier Science B.V. All rights reserve
d.