The voigt-type microwave Kerr effect in semiconductors with spherical constant energy surfaces1

A plane wave analysis is given for the free-carrier, microwave magneto-Kerr effect in semiconductors having spherical constant energy surfaces for the case of the applied static magnetic field perpendicular to the propagation direction (Voigt-type Kerr effect). The analysis is in terms of R_v, the complex polarization factor of the reflected wave. The behavior of R_v is considered in detail for low magnetic fields. Multiple-carrier conduction and energy-dependent scattering are shown to give rise to major contributions to R_v. Computer curves for |R_v|vs. μ_eB, $\text{n}\text{p}$ and ω are presented for parameters corresponding to InSb. Approximate expressions for R_v, which are valid for low magnetic field, high-loss conditions, are given and compared with curves computed from the more complex expressions. Room temperature data for R_v are presented for TE₁₁ waves in a circular waveguide. The dependence of R_v on magnetic flux density is shown for intrinsic InSb. The data are compared with the plane wave predictions. Experimental data for the magneto-Kerr effect are also given for magnetic fields slightly misaligned from the Voigt orientation. An empirical model is introduced which describes these data in terms of data for the Faraday and Voigt orientations of the magnetic field. This model is shown to be of value for alignment of the magnetic field in the Voigt orientation, and for measurement of the Voigt-type Kerr effect in the presence of any small, remaining longitudinal magnetic field component.