Vacuum variable-angle far-infrared ellipsometer

摘要

Highlights • We have build the vacuum variable-angle FIR ellipsometer able to measure from 50cm−1 to 680cm−1 in fully automatic regime. • The difference in Ψ and Δ in comparison with commercially available ellipsometers is less than 0.2° in Ψ and less than 1° in Δ. • We have to correct the angle of incidence because the beam of radiation is inhomogeneous and implemented the finity gold reflectivity correction. Abstract We present the design and performance of a vacuum far-infrared (∼50–680cm−1) ellipsometer with a rotating analyser. The system is based on a Fourier transform spectrometer, an in-house built ellipsometer chamber and a closed-cycle bolometer. The ellipsometer chamber is equipped with a computer controlled θ–2θ goniometer for automated measurements at various angles of incidence. We compare our measurements on SrTiO3 crystal with the results acquired above 300cm−1 with a commercially available ellipsometer system. After the calibration of the angle of incidence and after taking into account the finite reflectivity of mirrors in the detector part we obtain a very good agreement between the data from the two instruments. The system can be supplemented with a closed-cycle He cryostat for measurements between 5 and 400K.