Abstract
Complex permittivity spectra of a-axis and c-axis of the barium titanate single crystal were directly measured by the THz ellipsometer and the improved analysis program. Those spectra were also obtained by analysis method using four-parameter-semi-quantum model and polarized reflectivity spectra. As the result of analysis, the calculated ellipsometry constants and polarized reflectivity spectra showed good agreements for the observed value. Complex permittivity spectra measured by the ellipsometer was consistent with those obtained by reflectivity analysis. Infrared active phonons were also observed. Therefore complex permittivity spectra determined by four-parameter-semi-quantum model have the same accuracy as those directly measured by ellipsometer.
