Effect of Internal Reflection on Optical Faraday Rotation

Abstract

Recent Faraday rotation measurements in n‐type GaAs give an effective mass which is smaller than predicted by theory using accepted band parameters. These discrepancies can be interpreted by considering the multiple internal reflection effects in the measured rotation. The calculation was made for two cases: (1) when interference effects are directly observable (that is, λ and d are well defined and the optical path length of the internal reflected beam is shorter than coherence length), and (2) when an average value over a region of phase angle Δ≫»2π is measured. In the first case the rotation changes and oscillates as a function of wavelength and magnetic field. In the second case the rotation θ = VHd is given by the measured rotation γ minus a term which depends on the absorption, reflection, and the rotation in the sample.