Optical constants and critical-point parameters of GaAs from 0.73 to 6.60 eV

The optical constants of GaAs from 0.73 to 6.60 eV at 300 K were determined using rotating-analyzer spectroscopic ellipsometry. The setup includes a computer-controlled MgF2 Berek wave plate compensator, which allows exact measurements of the ellipsometric angle Δ below the band gap. Therefore, these data are very accurate over a broad range. I also determined the interband critical-point parameters of the E0, E0+Δ0, E1, E1+Δ1, E0′, and E2 transitions (energies, broadenings, phase angles, and amplitudes).