A numerical method developed previously [J. Appl. Phys. <b>80</b>, 4621 (1996)] has been extended to simulate the nonnormal-incidence reflectance-difference spectroscopy and transmittance-difference spectroscopy spectra of biaxial anisotropic (ε<sub>x</sub>≠ε<sub>y</sub>≠ε<sub>z</sub>) multilayer systems with finite thickness. It is demonstrated that, when the principal axes of the anisotropy layer are at certain orientations, a reflectance-difference spectrum can be separated into two spectra, namely, an in-plane anisotropic spectrum and an out-of-plane anisotropic spectrum. It is shown that the separation is valid for large in-plane anisotropy, i.e., |ε<sub>x</sub>−ε<sub>y</sub>|≈|ε<sub>x</sub>|, and an incident angle of ≤20°.
© 1998 Optical Society of America
Tat-Kun Kwok, K. C. Tam, and Paul K. Chu, "Interpretation of in-plane and out-of-plane anisotropic surface–interface reflectance and transmittance difference spectroscopy," J. Opt. Soc. Am. B 15, 1198-1204 (1998)