Investigation on 1.07 μm laser emission in Nd3+-doped sodium fluoroborate glasses

Spectroscopic and fluorescence properties of Nd3+ ions in sodium fluoroborate (SFB) glasses were prepared and characterized through optical absorption, emission and decay measurements. The energy level analysis was carried out using free-ion Hamiltonian model. Experimental oscillator strengths were determined by measuring the area encompassed by the absorption peaks recorded for 1.0 mol.% Nd3+- doped glasses. The Judd-Ofelt parameters (Ω2,4,6) were used to evaluate the laser characteristic parameters such as radiative transition probability (AR), radiative decay time (τR), fluorescence branching ratio (βR) and stimulated emission cross-section (σe) for the 4F3/2 metastable state. The fluorescence spectra for different concentrations of Nd3+ ions were recorded by exciting the samples at 514.5 nm Ar+ ion laser.