Far-Infrared Absorption to Test Anisotropy of Energy Gap in High Tc Superconducting Oxides

Abstract
The far-infrared absorption spectra are theoretically studied in poly-crystalline superconductors with anisotropic energy gap. The discrepancy between the recent far-infrared and tunneling experiments in the high T c oxides, (La, Sr)2CuO4, are explained by the anisotropy of the energy gap.