Optical constants of Pb1-xSnxTe alloys

The optical constants, such as the complex dielectric function, complex refractive index, absorption coefficient, and normal-incidence reflectivity, of Pb1-xSnxTe alloys have been determined using spectroscopic ellipsometry in the 1.15-5.5 eV photon-energy range at room temperature. The dielectric-function spectra [epsilon(E)] and their second-derivative spectra [d(2) epsilon(E)/dE(2)] were analyzed using a simplified model of the interband transitions. The composition dependence of the critical-point parameters and high-frequency dielectric constant has been obtained from these analyses. (C) 1996 American Institute of Physics.