Optical Response of AgCl and AgBr in the Near and Extreme Ultraviolet

Abstract
The extinction coefficients of AgCl and AgBr have been obtained down to liquid-helium temperature by observing the transmission of thin films in the near-uv direct exciton region (3.5-6.7 eV) and in the extreme uv (30-240 eV) using synchrotron radiation. The index of refraction was determined for both materials by a dispersion relation, and the optical constants were then constructed for AgCl in the range 3-240 eV, using all available data. Some interpretation of the exciton and band-to-band spectra is given. An estimate is made of the effective number of electrons which contribute to the absorption over a wide range of photon energies.