Charles C. Russell

Absorption intensities and emission cross sections of principal intermanifold and inter-stark transitions of Er3+(4f11) in polycrystalline ceramic garnet Y3Al5O12

A comparative spectroscopic study is performed on Er3+(4f11) ions doped in polycrystalline ceramic garnet Y3Al5O12 (YAG) and single-crystal laser rod, both containing nominal 50 at. % of Er3+. The standard Judd–Ofelt (JO) model is applied to the room-temperature absorption intensities of Er3+(4f11) transitions in both hosts to obtain the phenomenological intensity parameters. These parameters are subsequently used to determine the radiative decay rates, radiative lifetimes, and branching ratios of the Er3+ transitions from the upper multiplet manifolds to the corresponding lower-lying multiplet manifolds LJ2S+1 of Er3+(4f11) in these garnet hosts. The emission cross sections of the intermanifold Er3+I13∕24→I15∕24 (1.5 μm) transition as well as the principal inter-Stark transition Y1→Z4 (1550 nm) within the corresponding multiplet manifolds have been determined. The room-temperature fluorescence lifetimes of the I13∕24→I15∕24 (1.5 μm) transition in both polycrystalline ceramic and single-crystal YAG sample...

Spectroscopic analysis of the Er3+(4f11) absorption intensities in NaBi(WO4)2

A spectroscopic analysis is performed on Er3+ (4f11) ions doped in NaBi(WO4)2 (NBWO) in order to assess this material for its potential as a near-infrared laser. The Judd–Ofelt model is applied to the room-temperature absorption intensities of Er3+ (4f11) in NBWO to obtain the three phenomenological intensity parameters: Ω2=5.50×10−20 cm2, Ω4=1.00×10−20 cm2, and Ω6=0.71×10−20 cm2. The intensity parameters are then used to determine the radiative decay rates (emission probabilities), radiative lifetimes, and branching ratios for the Er3+ transitions from the excited state multiplet manifolds to the lower lying manifold states. Using the radiative decay rates for the Er3+ (4f11) transitions between the corresponding excited states and the lower lying states, the radiative lifetimes of eight excited states of Er3+ are determined in this host. Using the measured room temperature fluorescence lifetime of approximately 4.75 ms and the radiative lifetime of 5.63 ms as predicted by the Judd–Ofelt model for the 4I13/2→4I15/2 (1.52 μm) transition of Er3+ in NBWO the quantum efficiency is determined to be approximately 84% for this laser material.A spectroscopic analysis is performed on Er3+ (4f11) ions doped in NaBi(WO4)2 (NBWO) in order to assess this material for its potential as a near-infrared laser. The Judd–Ofelt model is applied to the room-temperature absorption intensities of Er3+ (4f11) in NBWO to obtain the three phenomenological intensity parameters: Ω2=5.50×10−20 cm2, Ω4=1.00×10−20 cm2, and Ω6=0.71×10−20 cm2. The intensity parameters are then used to determine the radiative decay rates (emission probabilities), radiative lifetimes, and branching ratios for the Er3+ transitions from the excited state multiplet manifolds to the lower lying manifold states. Using the radiative decay rates for the Er3+ (4f11) transitions between the corresponding excited states and the lower lying states, the radiative lifetimes of eight excited states of Er3+ are determined in this host. Using the measured room temperature fluorescence lifetime of approximately 4.75 ms and the radiative lifetime of 5.63 ms as predicted by the Judd–Ofelt model for the 4I...

Spectral analysis and energy-level structure of Er3+(4f11) in polycrystalline ceramic garnet Y3Al5O12

Absorption spectra obtained between 1550 and 440nm and fluorescence spectra obtained between 1700 and 1500nm are reported in a comparative spectroscopic study of polycrystalline ceramic Y3Al5O12 (YAG) and single-crystal laser rod YAG, both containing 50at.% Er3+ as a dopant in the garnet host. The spectra are observed in both samples at temperatures between 8K and room temperature. The detailed splitting of individual multiplet manifolds, LJ2S+1, Er3+(4f11), by the crystalline electric field is similar in both the ceramic sample and the single-crystal laser rod. With few exceptions, there is little shift in energy (few wave numbers) of individual Stark levels within a manifold, between dilute and concentrated Er3+ samples. This is not too surprising since Y3Al5O12 and Er3Al5O12 form a solid solution with the majority of Er3+ ions occupying cation sites having D2 symmetry in the garnet lattice over the entire solid solution range. As a check on the observed manifold splittings of Er3+ in ceramic YAG, we co...

Modeling the crystal-field splitting of energy levels of Er3+(4f11) in charge-compensated sites of KPb2Cl5

A point-charge lattice-sum model corrected for induced multipoles is used to investigate the crystal-field splitting of the LJ2S+1 energy levels of Er3+(4f11) ions that occupy charge-compensated sites in the laser host crystal KPb2Cl5. Spectroscopic data are reported and analyzed for Er3+ between 1550 and 440nm at cryogenic temperatures. The crystal-field (Stark) splitting of the ground-state manifold I15∕24 and the splitting of individual excited manifolds of Er3+ are established from analyses of temperature-dependent (hot band) absorption spectra. The analyses confirm the Stark splitting of the IJ4 and F9∕24 manifolds that are reported in the literature. From an analysis of the data, it appears that only one of the two possible Pb2+ sites serving as a charge-compensated site for Er3+ is involved in the optical activity of the Er3+ ions. From an examination of the crystallographic data of KPb2Cl5, we identify a possible site for the optically active Er3+ ion in the lattice and calculate the lattice-sum c...

Optical transitions, absorption intensities, and intermanifold emission cross sections of Pr3+(4f2) in Ca5(PO4)3F crystal host

A spectroscopic Judd–Ofelt investigation has been performed on Pr3+ ions doped in calcium fluorapatite, Ca5(PO4)3F, belonging to the apatite structure family. The standard Judd–Ofelt analysis was applied to the room temperature absorption intensities of Pr3+ transitions to determine the phenomenological intensity parameters: Ω2, Ω4, and Ω6. Values of the intensity parameters were subsequently used to determine the decay rates (emission probabilities), radiative lifetimes, and branching ratios of the principal intermanifold transitions of Pr3+ from the 3P2, 1D2, and 3P0 manifold states to the lower-lying manifolds. In addition, the room temperature fluorescence lifetimes and emission cross sections of the 3P2→3H5, 1D2→3H4, and 3P0→3F2 transitions were measured; these values were compared with those of Nd3+:yttritium–aluminum–garnet and Pr3+:Sr5(PO4)3 (known as S–FAP).

Spectra and energy levels of Er3+(4f11) in NaBi(WO4)2

Absorption and fluorescence spectra of Er3+(4f11) in crystals of NaBi(WO4)2 (NBW) are reported at temperatures between 15 K and room temperature. The absorption spectra include the details of the crystal-field splitting of 11 multiplet manifolds, 2S+1LJ of Er3+(4f11), spanning the wavelength range between 350 nm and 1550 nm. The crystal-field splitting of the ground-state 4I15/2, is obtained from an analysis of the fluorescence spectrum, 4S3/2→4I15/2. Spectra are characterized by inhomogeneous broadening due to the disordered crystal structure in which different valency cations, Na+ and Bi3+, statistically fill the S4 symmetry sites. The Er3+ ions likely replace the Bi3+ ions in these sites. A quasi-center model has been chosen to interpret the crystal-field splitting of each manifold, using D2d rather than S4 symmetry as the site for the rare-earth ion in the lattice. To test the feasibility of the model, the splitting of the energy levels of Nd3+ in NBW was carried out first and compared with experiment...

Spectroscopic analysis of the Er 3+ (4f 11 ) absorption intensities in NaBi(WO 4 ) 2

A spectroscopic analysis is performed on Er3+ (4f11) ions doped in order to assess this material for its potential as a near infrared laser. The Judd-Ofelt model is applied to the room temperature absorption intensities of Er3+ (4f11) in NaBi(WO4)2 to obtain the three phenomenological intensity parameters: Ω2 = 5.50 x 10-20 cm2, Ω4 = 1.00 x 10-20 cm2, and Ω6 = 0.71 x 10-20 cm2. The intensity parameters are then used to determine the radiative decay rates (emission probabilities), radiative lifetimes, and branching ratios for the Er3+ transitions from the excited state multiplet manifolds to the lower-lying manifold states. Using the radiative decay rates for the Er3+ (4f11) transitions between the corresponding excited states and the lower-lying states, the radiative lifetimes of eight excited states of Er3+ are determined in this host. Using the room temperature fluorescence lifetime and the radiative lifetime of the 4I13/2→4I15/2 (1.52 µm) transition of Er3+ in NaBi(WO4)2, the quantum efficiency is determined to be 84% for this laser material.

Spectroscopic analysis of the Er 3+ (4f 11) absorption intensities in NaBi(WO 4) 2

A spectroscopic analysis is performed on Er3+ (4f11) ions doped in order to assess this material for its potential as a near infrared laser. The Judd-Ofelt model is applied to the room temperature absorption intensities of Er3+ (4f11) in NaBi(WO4)2 to obtain the three phenomenological intensity parameters: Ω2 = 5.50 x 10-20 cm2, Ω4 = 1.00 x 10-20 cm2, and Ω6 = 0.71 x 10-20 cm2. The intensity parameters are then used to determine the radiative decay rates (emission probabilities), radiative lifetimes, and branching ratios for the Er3+ transitions from the excited state multiplet manifolds to the lower-lying manifold states. Using the radiative decay rates for the Er3+ (4f11) transitions between the corresponding excited states and the lower-lying states, the radiative lifetimes of eight excited states of Er3+ are determined in this host. Using the room temperature fluorescence lifetime and the radiative lifetime of the 4I13/2→4I15/2 (1.52 µm) transition of Er3+ in NaBi(WO4)2, the quantum efficiency is determined to be 84% for this laser material.

Spectroscopic analysis of the Er3+ (4f11) absorption intensities in NaBi(WO4)2

A spectroscopic analysis is performed on Er3+ (4f11) ions doped in order to assess this material for its potential as a near infrared laser. The Judd-Ofelt model is applied to the room temperature absorption intensities of Er3+ (4f11) in NaBi(WO4)2 to obtain the three phenomenological intensity parameters: Ω2 = 5.50 x 10-20 cm2, Ω4 = 1.00 x 10-20 cm2, and Ω6 = 0.71 x 10-20 cm2. The intensity parameters are then used to determine the radiative decay rates (emission probabilities), radiative lifetimes, and branching ratios for the Er3+ transitions from the excited state multiplet manifolds to the lower-lying manifold states. Using the radiative decay rates for the Er3+ (4f11) transitions between the corresponding excited states and the lower-lying states, the radiative lifetimes of eight excited states of Er3+ are determined in this host. Using the room temperature fluorescence lifetime and the radiative lifetime of the 4I13/2→4I15/2 (1.52 µm) transition of Er3+ in NaBi(WO4)2, the quantum efficiency is determined to be 84% for this laser material.