Development of an ellipsometry to the case of a coherent far infrared irradiation, low temperatures and small samples is described, including a decision of the direct and inverse problems of the convergent beam ellipsometry for an arbitrary wavelength, measurement technique and a compensating orientation of cryostat windows. Experimental results are presented: for a gold film and UBe13 single crystal at room temperature (lambda=119 um), temperature dependencies of the complex dielectric function of SrTiO3 (lambda=119, 84 and 28 um) and of YBa2Cu3O7-delta ceramic (lambda=119 um).
@article{arxiv.cond-mat/9805219,
title = {Low-temperature far-infrared ellipsometry of convergent beam},
author = {A. B. Sushkov and E. A. Tishchenko},
journal= {arXiv preprint arXiv:cond-mat/9805219},
year = {2015}
}