Determination of magneto-optical characteristics of hexaferrites from 200 GHz to 1THz using time domain spectroscopy

Gyrotropic, magnetically-hard hexaferrite materials, are very promising candidates to operate as quasi-optical non-reciprocal devices at high frequencies (> 90GHz), with the consequent advantage of obviating the need for requiring extra biasing magnets and avoiding low temperature demagnetization. In this paper, a THz TDS system is used to make measurements on a thin (2.02 mm thickness) hexaferrite plate for both parallel and perpendicular polarisation of the pump beam. From these data, the intrinsic circular-polarisation transmittances of both senses of polarisation are computed and these are analysed to determine the magneto-op tical constants of the hexaferrite plate over the range of 200 GHz to 1THz. Keywords: TDS, Hexaferrite, THz.