Comparative impact of Nd3+ ion doping concentration on near-infrared laser emission in lead borate glassy materials

Different concentrations (0.2-1.0 mol%) of Nd3+ doped lead borate glass (LB) systems were prepared by melt quenching technique and have been studied using XRD and optical studies. Based on the calculations of Judd-Ofelt (J-O) theory derived from the optical absorption spectra, three J-O parameters have been obtained. Various radiative parameters (such as radiative transition probability (A(rad)), branching ratio (beta(c)(at)), absorption cross-sections (Sigma), radiative lifetime (tau(R)) and etc., have been predicted through J-O parameters. Luminescence spectra were measured for all the samples. It has been observed that luminesce intensity gradually increased up to 0.8 mol % of Nd3+ and further increase in concentrations causes that the luminescence spectral intensity falls. This is proposed due to the concentration quenching of neodymium ions in the LB glass system. LB glass system with 0.8 mol % is found to be most intensive one in emission at 1.06 mu m related to F-4(3/2) -> I-4(11)/2 in near infrared (NIR) transition.