Piezoreflectivity of RbBr in the 6 and 14 eV Region Measured at Liquid N2 Temperatute

Piezoreflectivity Spectra of RbBr have been measured in the energy region between 6 and 14 eV at liquid nitrogen temperature. For the triplet structure at about 8 eV, large dichroic responses have been observed under the trigonal strain, while little dichroism under the tetragonal strain. The cubic deformation potentials of the structures are small in comparison with those of the \( \) excitons. These results are in good agreement with the piezoreflectivities of the triplet reflection band at about 8.6 eV in KBr. And the structures are assigned to the transitions L 4,5 - - L 6 ′ + , L 6 u - - L 6 + and L 61 - - L 6 + .