The results from spectral studies of PMMA modified by Nd3+ ions are present
ed. It is shown that the resulting composites are characterized by a high d
egree of homogeneity. The materials show luminescence in the IR spectral re
gion with maxima at 890 and 1059 nm. The intensity of luminescence increase
s in the presence of sensitizers, among which Xylenol Orange shows the high
est efficiency. The effect of the matrix nature manifests itself as a prono
unced widening of the luminescence lines due to Nd3+ ions. As temperature i
s decreased, the profile of the absorption bands changes and their intensit
y grows.