A study on the optical nonlinearity due to the Z 3 and Z 1,2 excitons of CuCl by the reflected four-wave mixed light generation

Abstract

We have demonstrated the generation of the reflected four-wave mixed light in the energy region from 3.185 eV to 3.320 eV including the highly absorptive region due to the Z 3 and Z 1,2 exciton bands of CuCl at 1.6 K. The mixed light signal is concluded to be due to the one-photon resonant contribution of the respective exciton level, from its polarization characteristics. The corresponding third order non-linear susceptibility is estimated from the data by the correction with the Fresnel factors which are calculated on the basis of the Pekar's Additional Boundary Condition.