Optimization of a femtosecond ellipsometer for gold photoreflectance studies

I develop a quantitative optimization procedure for femtosecond reflectance ellipsometer measurements. The femtosecond ellipsometer eliminates the need for separate thin-film reflectance and transmittance measurements and allows self-consistent determination of dielectric index changes of optically thick films on arbitrary substrates. I verify the optimization procedure and use the femtosecond ellipsometric measurements to investigate the photoreflectance of an optically thick gold film. A comparison of the extracted real and imaginary dielectric function components reveals evidence of thermalized and nonthermalized hot-electron populations.