Terahertz time domain magneto-optical ellipsometry in reflection geometry

Abstract

We propose and examine a method to reveal the diagonal and off-diagonal components of a dielectric tensor from THz magneto-optical Kerr effect (MOKE) measurements. The proposed method, which is based on time-domain THz measurement, does not involve any assumption on the magnitude of the magneto-optical constant. We apply this method to determine the dielectric tensor of n-type InAs in the spectral range from 0.5 to 2.5 THz and compare the results with those obtained in the framework of the conventional small magneto-optical response approximation. (SMRA). It is shown that when the probe frequency is lower than the frequency of longitudinal electromagnetic modes in the medium (e.g., below magnetoplasma or longitudinal phonon resonance) the SMRA-based analysis should be replaced with the method we developed even for small magneto-optical signals.