[Show abstract][Hide abstract] ABSTRACT: Until today dispersion analysis could not be successfully applied to evaluate oscillator parameters of modes that have their transition moments perpendicular to the surface of an anisotropic crystal or a layered medium. The main reason for this failure is that while such modes generate maxima in the external reflection spectra, which are obtained with polarized light parallel to the plane of incidence under nonzero angles of incidence, the positions of these maxima do not allow us to unambiguously trace back the oscillator positions. In contrast, total internal reflection of parallel polarized light generates minima at spectral positions close to the oscillator frequency. Starting from this observation, we found that a combined evaluation of external and total internal reflection spectra by dispersion analysis allows us to gain the oscillator parameters of perpendicular modes unambiguously.
No preview · Article · Dec 2011 · Journal of the Optical Society of America A
[Show abstract][Hide abstract] ABSTRACT: Based on Berreman's 4×4 matrix formalism [W. Berreman, J. Opt. Soc. Am. 62, 502 (1972)] we derive simplified expressions for the reflection formulas from the a–c crystal surface for non-normal incidence. The computational effort to apply the formulas was found to be only insignificantly higher than those for normal incidence, but considerably lower than for the general expressions. Consequently, the simplified formulas can be readily applied for dispersion analysis of spectra gained by spectroscopic ellipsometry or attenuated total reflection.
No preview · Article · Feb 2011 · Optics Communications