Study On Spectra Properties Of Rare Earth Ions Doped PMMA

Rare earth complex-doped polymers have promising applications not only in polymer light waveguides, fiber amplifiers and fiber lasers, but also in fiber gratings sensors, fiber optic groscope and other fiber detectors, because of their high doping concentrations, favorable fluorescence intensity and long fluorescence lifetimes. In this paper, fluorescence properties of polymers doped with rare earth ions were investigated in detail.Firstly, Judd-Ofelt theory and Werts-Jukes theory for calculating rare earth ion spectra parameters were given and compared. In our experiments, Werts-Jukes theory was chosen to calculate the fluorescence parameters of rare earth ions.Secondly, according to the energy level match principle between rare earth ions and ligands and other related regulations, HFA, TTFA and DBM were selected as ligands of Eu³⁺ and Sm³⁺ to synthesize Eu³⁺ chelates and Sm³⁺ chelates in their tris forms [Eu(TTFA)₃, Eu(HFA)₃, Eu(DBM)₃ and Sm(TTFA)₃, Sm(HFA)₃, Sm(DBM)₃]. The fluorescence properties of these chelates in benzene were investigated. It was found TTFA is the best ligand for Eu³⁺ and Sm³⁺. Based on this, the concentration (0.05⁰.5wt.%) influence of Eu(TTFA)₃ and Sm(TTFA)₃ on fluorescence properties in Eu(TTFA)₃ and Sm(TTFA)₃ doped PMMA was studied, respectively. The results showed that fluorescence intensity, fluorescence lifetime and fluorescence quantum efficiency increased with gradually increscent doped concentrations.Thirdly, we prepared Eu³⁺/Sm³⁺ codoped PMMA and firstly found that Sm³⁺ has a strong sensitization effect on the fluorescence properties of Eu³⁺. The fluorescence intensity of Eu³⁺ codoped in PMMA was much higher than that of only Eu³⁺-doped PMMA (10²0 times). Two possible sensitization mechanism are put forword.Finally, fabrication technics of polymer optical fiber preform rod was studied primarily, and different fabrication technics of undoped and doped PMMA was analysed, which provides a important reference for fabricating polymer optical fiber preform rod with better optical properties.Eu³⁺/Sm³⁺ codoped PMMA, because of much higher fluorescence intensity than that of only Eu³⁺-doped PMMA, might find promising applications not only in polymer light waveguides, fiber amplifiers and fiber lasers, but also in fiber gratings sensors, fiber optic groscope and other fiber detectors.