Z-scan measurements of the third-order optical nonlinearities and linear optical properties of 70TeO2 - 5MxOy - 10P2O5 - 10ZnO - 5PbF2 glasses doped with Er3+ ions modified by transition metals

The two photon absorption (TPA) coefficient (β), the nonlinear refractive index (n2 ), and the third order nonlinear optical susceptibility (χ<3> ) of tellurium dioxide glasses were investigated using the absorption spectra, normalized transmission, and Z-scan methods. We studied the influence of different transition metals, with and without the rare earth ion Er3+, on the nonlinear properties of these glasses. The experimental results show that (n2 ) and (β) are the highest for the glass consisting of cadmium oxide doped with rare earth ions. Consequently, the real and imaginary part of the third-order nonlinear optical susceptibility (χ<3>) is the highest for these materials. Moreover, the presence of Er3+ increased the NLO coefficients the all the examined samples. The Z-scan result confirms, the glasses exhibit self-focusing effects and the sign of the refractive nonlinearity is positive.