Polarization-Dependent Optical Properties of CdCl 2 and CdBr2 Single Crystals in the Vacuum Ultraviolet Region

摘要

The spectra of the fundamental optical response functions(η,κ,ε2, £2,ηeff) of CdCl2 and CdBr2 single crystalshave been derived in the region 4-12 eV for ordinaryray from the reflectivity spectra measured at room andliquid helium temperatures through the Kramers-Kronig procedure.The structures around the optical gap inthe ε2 spectrum are semi-quantitatively interpreted in termsof the optical transitions occuring at the γ point in theBrillouin zone. Polarization-dependent reflectivity measurementsperformed using the polished surfaces parallelto the c-axis have confirmed the interpretation and haveindicated further that the main structures observed in thedeep interband energy region are associated with the transitionsat the Z point. The energy band structure at highsymmetry critical points has been discussed on the oasisof the polarization-dependent spectral behaviors.