Interpretation of in-plane and out-of-plane anisotropic surface-interface reflectance and transmittance difference spectroscopy

A numerical method developed previously [J. Appl. Phys. 80, 4621 (1996)] has been extended to simulate the nonnormal-incidence reflectance-difference spectroscopy and transmittance-difference spectroscopy spectra of biaxial anisotropic (epsilon(x) not equal epsilon(y) not equal epsilon(z)) 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., \epsilon(x) - epsilon(y)\ approximate to \epsilon(x)\, and an incident angle of less than or equal to 20 degrees. (C) 1998 Optical Society of America [S0740-3224(98)01203-X].