Effect of Li 2 O substitution on structures and properties of Nd 3+ ‐doped Al(PO 3 ) 3 ‐Li 2 O glasses

99.8[(1−x%)Al(PO 3 ) 3 −x%Li 2 O]‐0.2Nd 2 O 3 glasses (mol%, x = 0, 5, 10, 15, 20) were prepared by high‐temperature melt and quenching method. The effect of Li 2 O replacing Al(PO 3 ) 3 on the physical, mechanical, and optical properties was correlated with the network structures and the local environment around Nd 3+ ions, which were obtained via Raman scattering spectra, solid‐state nuclear magnetic resonance (SSNMR), and pulse electron paramagnetic resonance (EPR) techniques. SSNMR results indicate that the addition of Li + ions cannot affect the connectivity between P and Al while it can break the P‐O‐P linkages resulting in the depolymerization of glass networks. EPR spectra indicate an increasing engagement of lithium around Nd 3+ ions with the increase of Li 2 O. The Judd‐Ofelt (J‐O) parameters Ω 4,6 increase, but Ω 2 decreases. The emission cross section at 1053 nm and quantum efficiency are improved by 27% and 31%, respectively. The work is helpful for understanding the evolution mechanism of emission properties and structures in Nd 3+ ‐doped Al(PO 3 ) 3 ‐Li 2 O phosphate glasses.