Optical constants of cupric sulfate in the infrared*

We have measured the spectral reflectance of a cupric sulfate single crystal for unpolarized radiation at near-normal incidence. Values of the refractive index n(ν) and the absorption index k(ν) have been obtained by subtractive Kramers-Kronig phase-shift analysis. The values of ∫ k(ν) dν for the characteristic SO4−− bands in the spectrum of the crystal are compared with values of ∫ k(ν) dν for these bands obtained by extrapolation of values of k(ν) determined for cupric sulfate solutions.