Optical properties of lissamine functionalized Nd3+ complexes in polymer waveguides and solution

Lissamine functionalized terphenyl-based Nd complexes are synthesized, and incorporated in deuterated dimethylsulfoxide solutions and partially fluorinated planar polymer waveguides. Optical excitation of the lissamine sensitizer around 500 nm, followed by intramolecular energy transfer to the Nd³⁺ ion, causes near-infrared photoluminescence (890, 1060, 1340 nm) due to intra-4f transitions in the Nd³⁺ ion. The intramolecular energy transfer rate is larger than 10⁷ s^-1. Due to the large absorption cross-section of the sensitizer (>10^-17 cm² around 500 nm), the Nd³⁺ is excited 10⁴ times more efficiently than in a pure complex, without sensitizer. The Nd³⁺ luminescence lifetime is relatively short, both in solution (2.2 µs) and in a polymer host (0.8 µs), which is attributed to coupling to vibrational states of nearby C-H and O-H groups. Spincoated fluorinated polymer planar waveguides, doped with these sensitized organic Nd complexes show excellent waveguide properties. Upon continued illumination, photodegradation is observed in the doped polymer films.