Azimuth dependent reflection anisotropy of oriented thin films

A simplified mathematical description of reflection anisotropy spectroscopy (RAS) measurements is presented. The RAS signals of a nanometer film with arbitrarily aligned dielectric axes are investigated. While RAS spectra are found to be relatively insensitive to tilting of the dielectric axes out of the surface plane, the variation of RAS signals with sample azimuthal orientation angle, theta(s), reveals a distinct sin theta(s) effect, superimposed on the previously observed sin 2 theta(s) and sin 4 theta(s) terms, which provides a measure of the tilt angle. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3246147]