Determination of the Optical Verdet Coefficient in Semiconductors and Insulators

Abstract

For many applications in research and development, it is of importance to know accurately the Verdet coefficients of semiconductors and insulators. The Verdet coefficient is defined as the single pass volume Faraday rotation per unit magnetic field and unit thickness. By applying the Voigt approximation for multiple internal reflections for coherent and incoherent radiation, one can determine the Verdet coefficient more accurately. The optical constants of the material must be known. The approximation can be applied to single and multiple layers of semiconductors or insulators. The advantage of this type of treatment is that it can be applied to different energy regions in semiconductors and insulators without directly employing a special microscopic model. Measurements of interband Faraday rotation in silicon and gallium arsenide, as well as measurements of the free carrier Faraday rotation in gallium arsenide and the changes in amplitude and phase of the measured rotation in a lead sulfide film on a substrate, are discussed.