Experimental results of an optical study of single-crystal zinc are presented. Components of the Zn dielectric function tensor were measured by spectroscopic ellipsometry in the 0.1-5 eV spectral range. In the NIR-VIS range, the dielectric function spectra show two clearly resolved, polarization-dependent optical features located at about 1 and 1.7 eV. The optical features were analyzed in a framework of parallel-band optical transitions. The performed theoretical calculations of the optical conductivity spectra well reproduce the experimental data with respect to positions, intensities, and polarization dependencies of the observed interband absorption peaks.

The interband optical transitions of zinc occur across the energy gaps which open at intersections of the Fermi surface with the effective Brillouin zone comprised of the 002 and 101 families of Bragg planes. Theoretical spectra of the interband Zn optical conductivities, calculated in a framework of the parallel‐band optical absorption, well reproduce the experimental data measured by spectroscopic ellipsometry (see the Editor's Choice article by Karpus et al. on pp. http://doi.wiley.com/10.1002/pssb.201552581). There is a good agreement in positions, spectral weights, and polarization dependencies of the theoretical and experimental interband absorption peaks. The determined energy gaps are of Δ002 = 0.9 eV and Δ101 = 1.54 eV. At the light polarization perpendicular to the optical axis, the interband transitions occur across the Δ101 gap only, and a single absorption peak manifests itself in a spectrum of the perpendicular optical conductivity. At the longitudinal polarization, the interband transitions occur across both Δ101 and Δ002 gaps, and the longitudinal optical conductivity spectrum is comprised of two corresponding peaks.