Optical spectroscopy of Nd3+ ions in poly(acrylic acid)

Nd3+ dissolved in solid poly(acrylic acid) was synthesized by polymerization of the monomer partially neutralized with neodymium hydroxide in aqueous solution. The monomer modification and the coordination of ligands to Nd3+ were confirmed by H-1 NMR spectroscopy. The measured oscillator strengths for transitions from the ground state to the main excited state manifolds compared favourably with calculated electric dipole oscillator strengths. The spontaneous emission rates, the fluorescence branching ratios and the stimulated emission cross sections of the F-4(3/2) -> I-4(9/2) -> F-4(3/2) -> I-4(11/2) and F-4(3/2) -> I-4(13/2) transitions, as well as the radiative lifetime and the quantum efficiency of the F-4(3/2) emitting level, were determined.