Effect of B2O3 content on structure and spectroscopic properties of neodymium-doped calcium aluminate glasses

Nd2O3-doped calcium aluminate glasses was synthesized with the following compositions: (100−x)(33Al2O3-62CaO-2MgO-3BaO)-xB2O3-0.5Nd2O3 (x = 0, 2.5, 5, 7.5, 10). The Raman, absorption, and emission spectra were measured to characterize the structure and spectroscopic properties of these glasses. The glass thermal stability was studied using differential scanning calorimetry (DSC) tests. Both the Raman spectra and DSC results indicated a decrease in the non-bridging oxygens (NBOs) in the [AlO4]− network with an increase in the B2O3 content. The J-O intensity parameter Ω2, covalency degree of the Nd-O bond, and emission bandwidth of the Nd3+ ions decreased with the B2O3 content. The stimulated emission cross-section and optical gain property increased with an increase in the B2O3 content. The tunable gain property and broadband emission feature of the Nd3+-doped CaO-Al2O3-B2O3-MgO-BaO calcium aluminate glass suggested a potential application to a high-energy ultra-short-pulse laser.