| Popis: |
We investigate the effect of irradiation by a UV pulse laser on the third-order optical nonlinearity of CuCl-microcrystallite-doped glass as a function of the irradiation’s shot number, energy density per pulse, and wavelength. The response time τ is estimated from the luminescence decay time of the CuCl excitons. The absolute value of the third-order nonlinear susceptibility χ(3) is measured by degenerate four-wave mixing. Values of both τ and χ(3) decrease after UV irradiation. The figure of merit for the optical nonlinearity, χ(3)/ατ, where α is the absorption coefficient, is almost constant before and after UV irradiation and is approximately 500 esu cm s-1 in the case of 8-nm CuCl microcrystallites. This value is 1 order of magnitude larger than that of CdSxSe1-x-microcrystallite-doped glasses. The mechanism by which τ and χ(3) are decreased is discussed, considering defects levels formed at the interface between CuCl microcrystallites and glass matrix. |
