Terahertz response of Bi-substituted rare-earth iron garnet

The terahertz optical and magneto-optical response of Bi-substituted rare-earth iron garnet film were studied from 0.2 to 1.2 THz. The thickness of film is 406 μm. The maximum transmittance is over 55% near the frequency point of 0.35 THz. When the external magnetic field change from -100 mT to +100 mT, the Faraday rotation angle is between -5° and +7°. Large Verdet constants approaching 270 °/T/mm are found. The overall change of ellipticity is relatively small.