Optical Constants of Germanium in the Region 1 to 10 ev

The reflectance, |r () |^2, of single-crystal germanium was measured in the range 0. 6 to 11. 3 ev. The phase, (), was computed from these data using the Kramers-Kronig relation between the real and imaginary parts of the complex function lnr=ln|r|+i. The optical constants, n and k, were then determined from the Fresnel reflectivity equation. The real part of the refractive index, n, has maxima of 5. 5 at 2. 07 ev and 4. 2 at 3. 2 ev. Above 6 ev, the index is very nearly 1. The extinction coefficient, k, shows maxima of 2. 0 at 2. 5 ev and 4. 2 at 4. 4 ev. Below 3. 5 ev, the results are in good agreement with the recent measurements of Archer. Beyond this point, they depart from his extrapolated curve.