Reply to ‘‘Comment on ‘Optical-transition cross sections involving impurities in semiconductors’ ’’

1985 ◽  
Vol 32 (2) ◽  
pp. 1351-1352 ◽  
Author(s):  
S. Chaudhuri
Keyword(s):  
Cross Sections ◽  
Optical Transition ◽  
Impurities In Semiconductors

Erbium Doped Tellurite Glasses

1991 ◽  
Vol 244 ◽  
Author(s):  
Jau-Sheng Wang ◽  
Elias Snitzer ◽  
George H. Sigel
Keyword(s):  
Excited State ◽  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
Optical Transition ◽  
Emission Cross Section ◽  
Excited State Absorption ◽  
Tellurite Glasses ◽  
Ground State Absorption ◽  
Erbium Doped

ABSTRACTThe results to be presented focus on the optimization of tellurite glass compositions which are suitable both for doping with erbium oxide as well as subsequent for fiber drawing. The laser related properties, such as fluorescence spectrum, lifetime, and optical transition cross sections will be presented. Judd-Ofelt parameters for erbium in the glasses have been exploited to predict fluorescence lifetime, excited state absorption(ESA), ground state absorption(GSA) and ground state fluorescence(GSF). For comparison, the absorption cross section, emission cross section, excited state absorption(ESA)/ground state absorption(GSA)(0.8μm pumping) and fluorescence terminating in the ground state(GSF)/excited state absorption(ESA) ratios are calculated for both Al2O3-SiO2 and tellurite glasses.

Interband optical transition spectra in GaAs quantum wires with rectangular cross sections

1997 ◽  
Vol 56 (4) ◽  
pp. 1958-1966 ◽  
Author(s):  
T. Sogawa ◽  
H. Ando ◽  
S. Ando ◽  
H. Kanbe
Keyword(s):  
Cross Sections ◽  
Quantum Wires ◽  
Optical Transition ◽  
Interband Optical Transition

scholarly journals Optical Transition Probabilities of Er3+Ions in ErBa3B9O18Crystal

2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Ming He ◽  
Tiezheng Liu ◽  
Junling Xiu ◽  
Yuanguang Tang ◽  
Zhihua Zhang
Keyword(s):  
Optical Absorption ◽  
Cross Sections ◽  
Transition Probabilities ◽  
Optical Transition ◽  
Radiative Lifetime ◽  
Absorption Data ◽  
Birefringent Crystal ◽  
Intensity Parameters ◽  
Thin Disk Laser ◽  
Er Doped

The optical absorption and emission intensity of luminescent and birefringent crystal ErBa3B9O18were examined from optical absorption data based on Judd-Ofelt theory. The three intensity parametersΩt(t=2,4,6) are 3.10 × 10−20, 0.87 × 10−20, and 1.80 × 10−20 cm2, respectively. From the obtained intensity parameters, the radiative probabilitiesAr, radiative lifetimeτf, fluorescence branching ratiosβc, and integrated emission cross sections∑have been calculated. In comparison with other Er-doped luminescent crystals, ErBa3B9O18may find application in thin disk laser.

Optical cross sections associated with deep-level impurities in semiconductors

1986 ◽  
Vol 33 (12) ◽  
pp. 8595-8601 ◽  
Author(s):  
J. Petit ◽  
G. Allan ◽  
M. Lannoo
Keyword(s):  
Cross Sections ◽  
Deep Level ◽  
Impurities In Semiconductors

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

An Analysis of Dissociation of Molecules in a High Resolution Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 486-487
Author(s):  
Mihir Parikh
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Sections ◽  
Resolving Power ◽  
Peak Intensity ◽  
Molecular Film ◽  
Resolution Electron ◽  
Dissociation Cross Section ◽  
High Resolution Electron Microscope ◽  
The Stability

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used

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