The Experts below are selected from a list of 125343 Experts worldwide ranked by ideXlab platform
John B Gruber - One of the best experts on this subject based on the ideXlab platform.
-
Spectral analysis and Energy-Level Structure of Er3+(4f11) in polycrystalline ceramic garnet Y3Al5O12
Journal of Applied Physics, 2005Co-Authors: John B Gruber, Dhiraj K Sardar, Charles C Russell, Toomas H Allik, Anmol S. Nijjar, Raylon M. Yow, Bahram ZandiAbstract: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...
-
Energy Level Structure and spectral analysis of nd3 4f3 in polycrystalline ceramic garnet y3al5o12
Journal of Applied Physics, 2004Co-Authors: John B Gruber, Dhiraj K Sardar, Toomas H Allik, Raylon M. Yow, Bahram ZandiAbstract:A detailed crystal-field splitting analysis is given for the 26 lowest-Energy multiplet manifolds, LJ2S+1, of Nd3+(4f3) in polycrystalline ceramic garnet Y3Al5O12 (YAG). The absorption spectra obtained between 8K and room temperature, and between 1750 and 350nm, and the fluorescence spectrum obtained at 8K and observed between 1450 and 875nm are analyzed for transitions between individual Energy (Stark) Levels that characterize the Energy-Level Structure of Nd3+ ions in D2 symmetry sites, replacing Y3+ ions in the garnet host lattice. A model Hamiltonian including atomic and crystal-field terms is diagonalized within the complete 4f3SLJMJ basis set which includes 364 states. The calculated splitting of the Nd3+ Energy Levels by the crystal field is compared with the experimental splitting observed in both the ceramic sample and a single-crystal laser rod. Both samples have approximately the same Nd3+ concentration, about 1at.%. By varying the atomic and crystal-field parameters, we obtain a standard devia...
-
electronic Energy Level Structure of trivalent holmium in yttrium aluminum garnet
Journal of Applied Physics, 1995Co-Authors: John B Gruber, Michael D Seltzer, Vincent J Pugh, F S RichardsonAbstract:The optical‐absorption spectrum of Ho3+:Y3Al5O12 (Ho:YAG) has been analyzed between 220 and 2160 nm under variable temperature conditions between 4 and 60 K. Measurements between 220 and 470 nm were obtained from a Ho:YAG crystal that contained 15 at. % holmium. A crystal containing 0.5 at. % holmium was used to obtain the spectrum between 470 and 2160 nm. Within the temperature and total spectral range, more than 1500 transitions due to Ho3+(4f10) were observed and attributed to transitions between individual crystal‐field (Stark) Levels of the ground‐state multiplet 5I8, and 49 different excited multiplet manifolds, 4f10(2S+1LJ), of trivalent holmium. From an analysis of these transitions it was possible to establish 419 of the 486 Stark Levels predicted below 45 000 cm−1. This large number of experimentally characterized Energy Levels provided a suitable basis for a detailed analysis of the 4f10(Ho3+) electronic state Structure in Ho:YAG. The analysis was carried out using a model Hamiltonian that assu...
G Renger - One of the best experts on this subject based on the ideXlab platform.
-
excitonic Energy Level Structure and pigment protein interactions in the recombinant water soluble chlorophyll protein i difference fluorescence line narrowing
Journal of Physical Chemistry B, 2011Co-Authors: Jörg Pieper, Harald Paulsen, I. Trostmann, Margus Ratsep, G Renger, Arvi FreibergAbstract:Difference fluorescence line-narrowing spectroscopy at 4.5 K was employed to investigate electron−phonon and electron−vibrational coupling strengths of the lower exciton Level of water-soluble chlorophyll-binding protein (WSCP) from cauliflower reconstituted with chlorophyll a or chlorophyll b, respectively. The electron−phonon coupling is found to be moderate with integral Huang−Rhys factors S in the order of 0.81−0.85. A weak dependence of S on excitation wavelength within the inhomogeneously broadened fluorescence origin band is attributed to a sizable contribution of nonresonant excitation that varies with excitation wavelength. The strongly asymmetric and highly Structured one-phonon profile is characterized by a peak phonon frequency (ωm) of ∼24 cm−1 and further discernible peaks at 48 and 88 cm−1, respectively. A structural assignment of this unusual one-phonon profile is proposed. As will be shown in the accompanying paper (part II) (DOI 10.1021/jp111457t), the parameters of electron−phonon coupli...
-
excitonic Energy Level Structure and pigment protein interactions in the recombinant water soluble chlorophyll protein ii spectral hole burning experiments
Journal of Physical Chemistry B, 2011Co-Authors: Jörg Pieper, Harald Paulsen, I. Trostmann, Margus Ratsep, Arvi Freiberg, Franzjosef Schmitt, Christoph Theiss, H J Eichler, G RengerAbstract:Persistent spectral hole burning at 4.5 K has been used to investigate the excitonic Energy Level Structure and the excited state dynamics of the recombinant class-IIa water-soluble chlorophyll-binding protein (WSCP) from cauliflower. The hole-burned spectra are composed of four main features: (i) a narrow zero-phonon hole (ZPH) at the burn wavelength, (ii) a number of vibrational ZPHs, (iii) a broad low-Energy hole at ∼665 and ∼683 nm for chlorophyll b- and chlorophyll a-WSCP, respectively, and (iv) a second satellite hole at ∼658 and ∼673 nm for chlorophyll b- and chlorophyll a-WSCP, respectively. The doublet of broad satellite holes is assigned to an excitonically coupled chlorophyll dimer. The lower-Energy holes at ∼665 and ∼683 nm for chlorophyll b- and chlorophyll a-WSCP, respectively, represent the lower exciton states. Taking into account the parameters of electron−phonon coupling, the lower exciton state can be assigned as the fluorescence origin. The lower exciton state is populated by two proce...
Bahram Zandi - One of the best experts on this subject based on the ideXlab platform.
-
Spectral analysis and Energy-Level Structure of Er3+(4f11) in polycrystalline ceramic garnet Y3Al5O12
Journal of Applied Physics, 2005Co-Authors: John B Gruber, Dhiraj K Sardar, Charles C Russell, Toomas H Allik, Anmol S. Nijjar, Raylon M. Yow, Bahram ZandiAbstract: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...
-
Energy Level Structure and spectral analysis of nd3 4f3 in polycrystalline ceramic garnet y3al5o12
Journal of Applied Physics, 2004Co-Authors: John B Gruber, Dhiraj K Sardar, Toomas H Allik, Raylon M. Yow, Bahram ZandiAbstract:A detailed crystal-field splitting analysis is given for the 26 lowest-Energy multiplet manifolds, LJ2S+1, of Nd3+(4f3) in polycrystalline ceramic garnet Y3Al5O12 (YAG). The absorption spectra obtained between 8K and room temperature, and between 1750 and 350nm, and the fluorescence spectrum obtained at 8K and observed between 1450 and 875nm are analyzed for transitions between individual Energy (Stark) Levels that characterize the Energy-Level Structure of Nd3+ ions in D2 symmetry sites, replacing Y3+ ions in the garnet host lattice. A model Hamiltonian including atomic and crystal-field terms is diagonalized within the complete 4f3SLJMJ basis set which includes 364 states. The calculated splitting of the Nd3+ Energy Levels by the crystal field is compared with the experimental splitting observed in both the ceramic sample and a single-crystal laser rod. Both samples have approximately the same Nd3+ concentration, about 1at.%. By varying the atomic and crystal-field parameters, we obtain a standard devia...
Arvi Freiberg - One of the best experts on this subject based on the ideXlab platform.
-
excitonic Energy Level Structure and pigment protein interactions in the recombinant water soluble chlorophyll protein i difference fluorescence line narrowing
Journal of Physical Chemistry B, 2011Co-Authors: Jörg Pieper, Harald Paulsen, I. Trostmann, Margus Ratsep, G Renger, Arvi FreibergAbstract:Difference fluorescence line-narrowing spectroscopy at 4.5 K was employed to investigate electron−phonon and electron−vibrational coupling strengths of the lower exciton Level of water-soluble chlorophyll-binding protein (WSCP) from cauliflower reconstituted with chlorophyll a or chlorophyll b, respectively. The electron−phonon coupling is found to be moderate with integral Huang−Rhys factors S in the order of 0.81−0.85. A weak dependence of S on excitation wavelength within the inhomogeneously broadened fluorescence origin band is attributed to a sizable contribution of nonresonant excitation that varies with excitation wavelength. The strongly asymmetric and highly Structured one-phonon profile is characterized by a peak phonon frequency (ωm) of ∼24 cm−1 and further discernible peaks at 48 and 88 cm−1, respectively. A structural assignment of this unusual one-phonon profile is proposed. As will be shown in the accompanying paper (part II) (DOI 10.1021/jp111457t), the parameters of electron−phonon coupli...
-
excitonic Energy Level Structure and pigment protein interactions in the recombinant water soluble chlorophyll protein ii spectral hole burning experiments
Journal of Physical Chemistry B, 2011Co-Authors: Jörg Pieper, Harald Paulsen, I. Trostmann, Margus Ratsep, Arvi Freiberg, Franzjosef Schmitt, Christoph Theiss, H J Eichler, G RengerAbstract:Persistent spectral hole burning at 4.5 K has been used to investigate the excitonic Energy Level Structure and the excited state dynamics of the recombinant class-IIa water-soluble chlorophyll-binding protein (WSCP) from cauliflower. The hole-burned spectra are composed of four main features: (i) a narrow zero-phonon hole (ZPH) at the burn wavelength, (ii) a number of vibrational ZPHs, (iii) a broad low-Energy hole at ∼665 and ∼683 nm for chlorophyll b- and chlorophyll a-WSCP, respectively, and (iv) a second satellite hole at ∼658 and ∼673 nm for chlorophyll b- and chlorophyll a-WSCP, respectively. The doublet of broad satellite holes is assigned to an excitonically coupled chlorophyll dimer. The lower-Energy holes at ∼665 and ∼683 nm for chlorophyll b- and chlorophyll a-WSCP, respectively, represent the lower exciton states. Taking into account the parameters of electron−phonon coupling, the lower exciton state can be assigned as the fluorescence origin. The lower exciton state is populated by two proce...
Jörg Pieper - One of the best experts on this subject based on the ideXlab platform.
-
excitonic Energy Level Structure and pigment protein interactions in the recombinant water soluble chlorophyll protein i difference fluorescence line narrowing
Journal of Physical Chemistry B, 2011Co-Authors: Jörg Pieper, Harald Paulsen, I. Trostmann, Margus Ratsep, G Renger, Arvi FreibergAbstract:Difference fluorescence line-narrowing spectroscopy at 4.5 K was employed to investigate electron−phonon and electron−vibrational coupling strengths of the lower exciton Level of water-soluble chlorophyll-binding protein (WSCP) from cauliflower reconstituted with chlorophyll a or chlorophyll b, respectively. The electron−phonon coupling is found to be moderate with integral Huang−Rhys factors S in the order of 0.81−0.85. A weak dependence of S on excitation wavelength within the inhomogeneously broadened fluorescence origin band is attributed to a sizable contribution of nonresonant excitation that varies with excitation wavelength. The strongly asymmetric and highly Structured one-phonon profile is characterized by a peak phonon frequency (ωm) of ∼24 cm−1 and further discernible peaks at 48 and 88 cm−1, respectively. A structural assignment of this unusual one-phonon profile is proposed. As will be shown in the accompanying paper (part II) (DOI 10.1021/jp111457t), the parameters of electron−phonon coupli...
-
excitonic Energy Level Structure and pigment protein interactions in the recombinant water soluble chlorophyll protein ii spectral hole burning experiments
Journal of Physical Chemistry B, 2011Co-Authors: Jörg Pieper, Harald Paulsen, I. Trostmann, Margus Ratsep, Arvi Freiberg, Franzjosef Schmitt, Christoph Theiss, H J Eichler, G RengerAbstract:Persistent spectral hole burning at 4.5 K has been used to investigate the excitonic Energy Level Structure and the excited state dynamics of the recombinant class-IIa water-soluble chlorophyll-binding protein (WSCP) from cauliflower. The hole-burned spectra are composed of four main features: (i) a narrow zero-phonon hole (ZPH) at the burn wavelength, (ii) a number of vibrational ZPHs, (iii) a broad low-Energy hole at ∼665 and ∼683 nm for chlorophyll b- and chlorophyll a-WSCP, respectively, and (iv) a second satellite hole at ∼658 and ∼673 nm for chlorophyll b- and chlorophyll a-WSCP, respectively. The doublet of broad satellite holes is assigned to an excitonically coupled chlorophyll dimer. The lower-Energy holes at ∼665 and ∼683 nm for chlorophyll b- and chlorophyll a-WSCP, respectively, represent the lower exciton states. Taking into account the parameters of electron−phonon coupling, the lower exciton state can be assigned as the fluorescence origin. The lower exciton state is populated by two proce...