Nonlinear optical properties in Pr3+-Er3+-codoped tellurite glasses

In this investigation, we systematically probe the structural, optical, and, notably, the nonlinear optical properties of Pr3+-Er3+-codoped tellurite glasses to understand the potential new functionalities of the glass and, thus, their applicability. The glass samples were synthesized employing the melt-quenching technique and subsequently characterized using X-ray photoelectron spectroscopy (XPS) and femtosecond (fs) pulse Z-scan measurements at 720 and 750 nm wavelengths. XPS analyses unveiled increased non-bridging oxygens (NBO) with ascending Pr2O3 content. It was observed that the increasing concentrations of Pr3+ ions show a linear dependence with the increase of NBO in the glass network (r2>0.95). This trend further supported the formation of Te3+ ions via the oxidation of Te4+ for charge compensation and was affirmed by a decrement in average Te−O bond as Pr2O3 concentrations increased. The tellurite glasses showcased positive nonlinear refraction on the nonlinear optical (NLO) front. The rise in n2 values was directly linked to the Pr2O3 content, a phenomenon attributed to the increased presence of non-bridging oxygens and the inherent polarizability of Pr3+ ions. Collectively, our findings offer pivotal insights into the modulation of NLO attributes in Er3+-doped tellurite glasses via Pr3+ ion doping, underscoring their potential in advanced NLO device applications.