This study aims to investigate the optical properties of multiple neodymium-doped gadolinium compounds as a means to examine their eligibility as optical probes for fluorescence imaging. GdVO${}_4$, GdPO${}_4$, GdAlO${}_3$, Gd${}_2$SiO${}_5$ and Gd${}_3$Ga${}_5$O${}_{12}$ (GGG) samples were synthesized through solid-state reactions with varying neodymium doping levels to compare their optical properties in great detail. The optimal doping concentration was generally found to be approximately 2%. Furthermore, the luminescence lifetime, which is a valuable parameter for time-gated imaging, was determined to range from 276 down to 14 µs for the highest doping concentrations, resulting from energy transfer and migration assisted decay.