High excited state cross-section of the indocyanine green solutions

2006 ◽  
Author(s):  
D. C. J. Rezende ◽  
L. De Boni ◽  
C. R. Mendonca
Keyword(s):  
Excited State ◽  
Indocyanine Green ◽  
Cross Section ◽  
High Excited State

scholarly journals 0+ States of 8Be

1968 ◽  
Vol 21 (3) ◽  
pp. 239 ◽  
Author(s):  
FC Barker ◽  
HJ Hay ◽  
PB Treacy
Keyword(s):  
Excited State ◽  
Excited States ◽  
Cross Section ◽  
Scattering Data ◽  
Excitation Energies ◽  
R Matrix ◽  
Channel Radius

The light even nuclei with A ;;;. 10 have 0+ excited states near 6 MeV, probably with large (X-particle reduced widths. A similar state in BBe would be very broad. Evidence for 0+ excited states in BBe has been obtained here using many-level R-matrix fits to known (X-(X scattering data, but the excitation energies depend strongly on the assumed channel radius. For a simultaneous fit to the 9Be(p, d)BBe cross section, assuming these higher states are not strongly populated, the channel radius is restricted to (7~~) fm, implying a 0+ excited state at (6=f3) MeV of width (9=f4) MeV.

scholarly journals Ultrafast processes triggered by one- and two-photon excitation of a photochromic and luminescent hydrazone

2019 ◽  
Vol 15 ◽  
pp. 2438-2446 ◽  
Author(s):  
Alessandro Iagatti ◽  
Baihao Shao ◽  
Alberto Credi ◽  
Barbara Ventura ◽  
Ivan Aprahamian ◽  
...  
Keyword(s):  
Excited State ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Transient Absorption ◽  
Solvent Polarity ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Time Resolved ◽  
Two Photon Absorption ◽  
Two Photon

In this work we apply a combination of steady state and time resolved luminescence and absorption spectroscopies to investigate the excited-state dynamics of a recently developed molecular photoswitch, belonging to the hydrazone family. The outstanding properties of this molecule, involving fluorescence toggling, bistability, high isomerization quantum yield and non-negligible two-photon absorption cross section, make it very promising for numerous applications. Here we show that the light induced Z/E isomerization occurs on a fast <1 ps timescale in both toluene and acetonitrile, while the excited state lifetime of the Z-form depends on solvent polarity, suggesting a partial charge transfer nature of its low lying excited state. Time-resolved luminescence measurements evidence the presence of a main emission component in the 500–520 nm spectral range, attributed to the Z-isomer, and a very short living blue-shifted emission, attributed to the E-isomer. Finally, transient absorption measurements performed upon far-red excitation are employed as an alternative method to determine the two-photon absorption cross-section of the molecule.

White upconversion emission in Yb3+/Tm3+/Ho3+ doped SrMoO4 nanocrystals by high excited state energy transfer

2013 ◽  
Vol 550 ◽  
pp. 509-513 ◽  
Author(s):  
Dongyu Li ◽  
Yuxiao Wang ◽  
Xueru Zhang ◽  
Guang Shi ◽  
Gang Liu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Excited State ◽  
State Energy ◽  
Upconversion Emission ◽  
High Excited State ◽  
Excited State Energy

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.

The negative ions of atomic and molecular oxygen

1943 ◽  
Vol 239 (806) ◽  
pp. 269-304 ◽  
Keyword(s):  
Excited State ◽  
Molecular Oxygen ◽  
Cross Section ◽  
Negative Ions ◽  
Excited Configuration ◽  
Virtual Level ◽  
Resonance Effects ◽  
Low Pressures ◽  
Charged Ions ◽  
Oppositely Charged

The properties, modes of formation and of destruction of the negative ions of atomic and molecular oxygen are examined in detail, using quantal theory to interpret and amplify the somewhat meagre experimental information. A detailed examination of the (Lf)2 (2j)2 (2/>)4 (3s) excited configuration of O - is made in an attempt to decide whether it can give rise to the observed stable excited state in which the attached electron has nearly zero binding energy. This is important in attachment, detachment and electron scattering phenomena as resonance effects will occur if the configuration is on the verge of stability or instability. The Hartree-Fock equations have been solved for the deepest (4P and 2P) terms of this configuration, polarization effects being allowed for by the introduction of a term involving a polarizability p regarded as an adjustable parameter. Stable excited P terms are only found when p is two to four times as large as the polarizability of O deduced from the refractivity of 0 2. This does not completely exclude identification of the excited state as belonging to the configuration considered. To examine the possible resonance effects, radiative attachment and detachment rates are calculated for a variety of values of the polarizability parameter p. The rapid variation of these quantities with p in the region where a real or virtual level of the 3^ electron, with small energy, exists makes it unlikely that definite theoretical values can be given until more information as to the proper value of p is forthcoming. Meanwhile, the parameter p provides a convenient correlation of the probabilities of the two processes with the energy of the 3* electron. The other possible attachment and detachment processes involving O and 0 ~ are also discussed. In order to interpret experiments on attachments of electron swarms in 0 2 and to decide how to extrapolate the results to low pressures, the deep electronic states of O^" are considered in detail, employing the empirical methods commonly used in studying molecular structure. It is found that their distribution is such as to make it most unlikely that Ofl~ ions can be formed with appreciable probability by attachment of slow electrons to Oz at low pressures, by a pressure-independent process other than direct radiative attachment. However, considerable difficulties and uncertainties are found in attempting a detailed interpretation of the experimental results at the higher pressures and more experiments are required. In the final section the formation of pairs of oppositely charged ions from molecules by impact of electrons or light quanta is investigated in terms of the theory of the crossing of molecular potentialenergy curves. The same theory is also applied to obtain information as to the possible magnitude of the cross-section for mutual neutralization of oppositely charged ions by electron transfer on impact. It is shown that a cross-section of between 10~13 and 10-12 cm.2 is quite likely to occur for atomic oxygen ions, but the occurrence of one as high as 1CH1 cm.2 is most unlikely. A detailed summary of results and conclusions is given.

Solvent Effects on C60 Excited State Cross Sections

1994 ◽  
Vol 374 ◽  
Author(s):  
Daniel G. McLean ◽  
Donna M. Brandelik ◽  
Mark C. Brant ◽  
Richard L. Sutherland ◽  
Lynn Frock
Keyword(s):  
Excited State ◽  
Cross Section ◽  
Cross Sections ◽  
Solvent Effects ◽  
Nonlinear Absorption ◽  
Equation System ◽  
Survey Study ◽  
Absorption Properties ◽  
Absorption Measurements ◽  
Initial Transmission

AbstractA survey study of solvent effects on the linear and nonlinear absorption properties of C60 has been done. The nonlinear absorption measurements are done at 694 nm with a Q-switched Nd:YAG pumped dye laser. In conjunction with this study a three level rate equation system has been solved analytically and the model results used to extract effective excited state cross sections. A difference and a ratio are calculated from the effective excited state cross section and the ground state cross section. The analysis demonstrates that it is this difference and the initial transmission which determine the critical fluence for the onset of nonlinear absorption. The saturation behavior is determined by the ratio of the cross sections and the initial transmission. Based on these findings C60 is shown to have some of the highest reported nonlinear absorption properties at 694 nm. The effective excited state cross sections at 694 nm are reported for the solutions and correlations to the solvent types demonstrated.

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