Reflection anisotropy spectroscopy: An optical probe of surfaces and interfaces

Reflection anisotropy spectroscopy (RAS) is a nondestructive surface-sensit ive optical probe capable of operation within a wide range of environments. RAS has been applied to semiconductor surfaces and has found use as an in situ, monitor of semiconductor growth. Surface sensitivity has been demonst rated with the detection of reconstructions, dimer orientations, and adsorp tion. More recently, RAS has been used to probe the surface optical propert ies of metals. In this article, some aspects of the RAS technique are descr ibed, including an analysis of the passage of polarized light through the R A spectrometer, which results in frequency-dependent terms related to the r eal and imaginary RA. ii short review of recent applications of RAS is give n.