Third-order optical nonlinear features of Er3+ and Pr3+ activated multicomponent borate glasses in nanosecond pulse regime: A comparative study

In the current work, the borate-based glass specimens bearing composition (mol %) 5Na(2)O-10ZnO-10Bi(2)O(3). (75.x)B2O3-xRE (where RE = Er2O3 and Pr6O11, and x ranges from 0 to 5 mol %) were synthesized by conventional melt-quench method. The effect of rare earth ions concentration on photonic nonlinearities has been explored by the Z-scan method under the pumping of 532 nm in a nanosecond pulse regime. The Z-signatures revealed the occurrence of nonlinear absorption and refraction in the studied glass specimens. The nonlinear optical features were improved with respect to the rare earth concentration. The nonlinear optical features were superior for Er3+ doped glasses compared to Pr3+ doped glasses. This greatness of nonlinear optical features in Er3+ doped glasses was attributed to the existence of a large number of electrons (11 electrons) in the 4f outer shell compared to those existing in the 4f outer shell of Pr3+ (2 electrons). The enhancement of nonlinear gap features was also attributed to the creation of non-bridging oxygens in the host network when rare earths are loaded into the composition. The nonlinear photonic outcomes endorse that heavily Er3+ loaded glasses are superior over Pr3+ doped glasses for nonlinear optical device fabrications to work in the visible region.