Douglas M. Dee

Publications (2)4.34 Total impact

• Article: Optical characterization and ligand-field splitting of Er3+(4f11) energy levels in a fluorine containing tellurite glass

  Dhiraj K. Sardar, Douglas M. Dee, Kelly L. Nash, Raylon M. Yow, John B. Gruber, Radhaballav Debnath
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  ABSTRACT: An in-depth spectroscopic study is performed on Er ³⁺(4f¹¹) ions doped into a fluorine containing (lead, lanthanum)-tellurite glass host, containing nominal 1.93 at. % of Er ³⁺ . The standard Judd-Ofelt (JO) model is applied to the room temperature absorption intensities of Er ³⁺(4f¹¹) transitions in the tellurite glass host to obtain three phenomenological intensity parameters, Ω₂ , Ω₄ , and Ω₆ . These parameters are subsequently used to determine the radiative decay rates, radiative lifetimes, and branching ratios of the Er ³⁺ transitions from the upper multiplet manifolds to the corresponding lower-lying multiplet manifolds ^2S+1L_J of Er ³⁺(4f¹¹) in the tellurite glass host. The emission cross sections of the intermanifold Er ³⁺ ⁴I_13/2→⁴I_15/2 (1.5 μ m ) and ⁴S_3/2→⁴I_15/2 (540 nm ) transitions have been determined. The room temperature fluorescence lifetimes of the ⁴I_13/2→⁴I_15/2 and ⁴S_3/2→⁴I_15/2 transitions in this tellurite glass host were also measured. From the radiative lifetime determined from the JO model and measured fluorescence lifetime, the quantum efficiency of this material was also determined. The spect- roscopic properties were compared with those of Er ³⁺(4f¹¹) in other halotellurite glass hosts. We also analyzed the band structure observed in the absorption spectra of Er ³⁺ in the tellurite glass at 8 K . The structure can be interpreted in terms of the ligand-field splitting of the energy levels of the Er ³⁺ ion in the local environment established by the glass matrix into which Er ₂ O ₃ has been introduced. The spectroscopic analysis of Er ³⁺(4f¹¹) suggests that the tellurite glass is an excellent candidate for various photonic applications.
  Journal of Applied Physics 11/2007; · 2.17 Impact Factor
• Source

  Available from: John B. Gruber

  Article: Optical absorption intensity analysis and emission cross sections for the intermanifold and the inter-Stark transitions of Nd3+(4f 3) in polycrystalline ceramic Y2O3

  Dhiraj K. Sardar, Douglas M. Dee, Kelly L. Nash, Raylon M. Yow, John B. Gruber
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  ABSTRACT: Spectroscopic properties have been characterized for trivalent neodymium doped polycrystalline ceramic ytttria, Nd ³⁺: Y ₂ O ₃ . The Judd-Ofelt [Phys. Rev. 127, 750 (1962); J. Chem. Phys. 37, 511 (1962)] analysis has been applied to the room temperature absorption spectrum to determine the radiative decay rates and branching ratios of Nd ³⁺ transitions from the ⁴F_3/2 metastable manifold to the ⁴I_J lower-lying multiplet manifolds. The quantum efficiency is determined from the measured fluorescence lifetime and the radiative lifetime of the ⁴F_3/2 manifold state. In addition, a detailed characterization of the Stark energy levels of the ⁴I_9/2 and ⁴I_11/2 manifolds has been performed using the room temperature fluorescence spectra for the ⁴F_3/2→⁴I_9/2 and ⁴F_3/2→⁴I_11/2 transitions of Nd ³⁺(4f³) in ceramic Y ₂ O ₃ . The emission cross sections of the ⁴F_3/2→⁴I_9/2 and ⁴F_3/2→⁴I_11/2 intermanifold transitions have been determined. Also, the peak emission cross sections of the principal inter-Stark peak transitions R₁→X₅ and R₁→Y₂ have been determined. Finally, the spectroscopic properties of ceramic Nd ³⁺: Y</ro- man>₂ O ₃ are compared with those of ceramic Nd ³⁺: YAG as well as single crystals of Nd ³⁺: Y ₂ O ₃ and Nd ³⁺: YAG .
  Journal of Applied Physics 01/2007; · 2.17 Impact Factor