A combination of ellipsometric and photometric measurements provides a
convenient and accurate method for the determination of the optical p
roperties of thick polymer films. Of course, a reasonably good surface
and layer quality is necessary. Multiple reflections in the thick fil
m and thus incoherent superposition causes partial depolarization of t
he reflected or transmitted light. Therefore, the Mueller matrix eleme
nts of these layers are measured and compared to calculated ones. A re
lationship between Jones and Mueller matrices originally given for ran
dom media, is used to derive the formulas for the Mueller matrix eleme
nts of these anisotropic thick films. This relationship can also be ap
plied to other incoherent effects in spectroscopic ellipsometry, such
as depolarization upon reflection by a sample with a varying film thic
kness or by a layer with fluctuating optical constants. (C) 1998 Elsev
ier Science S.A.