Infrared absorption spectrum and faraday rotation of hot- pressed CdCr2S4

Hot-pressed CdCr2S4has been prepared which has high optical quality in the infrared. The absorption coefficient and Faraday rotation have been measured in the wavelength range between 3 and 15 μm. The absorption coefficient was measured both spectrometrically, which includes absorption and scattering, and calorimetrically at 10.6 μm with a CO2laser, which measures only the absorption. At 10.6 μm both methods give a value of about 3.5 cm^-1, indicating that scattering is not important. The Faraday rotation measurements agree essentially with those found for single-crystal CdCr2S4by Wittekoek and Bongers. At 10.6 μm and 80°K the rotation is 120 deg/cm at 6.5 kOe, giving a figure of merit of about 7.5-deg rotation per dB absorption. Therefore, application of this material to magnetooptical devices may be possible using liquid nitrogen as a coolant.