Sensitized Fluorescence in Vapors of Alkali Atoms. XIII. 62P1/2−62P3/2 Excitation Transfer in Rubidium, Induced in Collisions with Noble Gas Atoms

1972 ◽  
Vol 50 (16) ◽  
pp. 1826-1832 ◽  
Author(s):  
I. Siara ◽  
E. S. Hrycyshyn ◽  
L. Krause
Keyword(s):  
Fine Structure ◽  
Cross Sections ◽  
Noble Gas ◽  
Excitation Transfer ◽  
Fluorescent Intensity ◽  
Rubidium Vapor ◽  
Sensitized Fluorescence ◽  
Fine Structure Splitting ◽  
Alkali Atoms ◽  
Structure Splitting

The cross sections for excitation transfer between the 62P fine-structure substates in rubidium, induced in collisions with noble gas atoms, have been determined in a series of sensitized fluorescence experiments. Mixtures of rubidium vapor and noble gases at pressures varying in the range 0–5 Torr were irradiated with each component of the second 2P rubidium doublet in turn and the following cross sections for 2P mixing were obtained from measurements of sensitised-to-resonance fluorescent intensity ratios. Rb–He: Q12(2P1/2 → 2P3/2) = 29.3 Å2; Q21(2P1/2 ← 2P3/2) = 19.0 Å2. Rb–Ne: Q12 = 10.3 Å2; Q21 = 6.4 Å2. Rb–Ar: Q12 = 24.0 Å2; Q21 = 14.9 Å2. Rb–Kr: Q12 = 23.2 Å2; Q21 = 14.6 Å2. Rb–Xe: Q12 = 43.9 Å2; Q21 = 27.7 Å2 In their dependence on the magnitude of the fine-structure splitting, the values are consistent with previously determined cross sections for mixing in the first and third 2P doublets of alkali atoms.

Inelastic Collisions between Excited Alkali Atoms and Molecules. VIII. 62P1/2–62P3/2 Mixing and Quenching in Mixtures of Rubidium with H2, HD, D2, N2, CH4, and CD4

1973 ◽  
Vol 51 (3) ◽  
pp. 257-265 ◽  
Author(s):  
I. N. Siara ◽  
L. Krause
Keyword(s):  
Fine Structure ◽  
Cross Sections ◽  
Ground State ◽  
Inelastic Collisions ◽  
Fluorescent Intensity ◽  
Rubidium Vapor ◽  
Sensitized Fluorescence ◽  
Molecular Gases ◽  
Alkali Atoms ◽  
Intensity Ratios

Excitation transfer between the 62P fine-structure substates in rubidium, induced in inelastic collisions with ground-state molecules, has been studied using techniques of sensitized fluorescence. Rubidium vapor in mixtures with various molecular gases was irradiated with each component of the 2P rubidium doublet in turn, and measurements of sensitized-to-resonance fluorescent intensity ratios yielded the following mixing cross sections Q12(2P1/2 → 2P3/2) and Q21(2P1/2 ← 2P3/2), as well as effective quenching cross sections Q1X(2P1/2 → 2XJ″) and Q2X(2P3/2 → 2XJ″). For collisions with H2: Q12(2P1/2 → 2P3/2) = (41 ± 5) Å2; Q21(2P1/2 ← 2P3/2) = (26 ± 3) Å2; Q1X(2P1/2 → 2XJ″) = (36 ± 9) Å2; Q2X(2P3/2 → 2XJ″) = (31 ± 8) Å2. For HD: Q12 = (42 ± 5) Å2; Q21 = (27 ± 4) Å2; Q1X = (47 ± 13) Å2; Q2X = (38 ± 10) Å2. For D2: Q12 = (42 ± 5) Å2; Q21 = (27 ± 4) Å2; Q1X = (28 ± 8) Å2; Q2X = (21 ± 7) Å2. For N2: Q12 = (107 ± 15) Å2; Q21 = (70 ± 10) Å2; Q1X = (128 ± 44) Å2; Q2X = (126 ± 33) Å2. For CH4: Q12 = (38 ± 6) Å2; Q21 = (24 ± 3) Å2; Q1X = (129 ± 41) Å2; Q2X = (114 ± 37) Å2. For CD4: Q12 = (52 ± 7) Å2; Q21 = (34 ± 5) Å2; Q1X = (82 ± 30) Å2; Q2X = (76 ± 22) Å2. An analysis of these results suggests the possibility of resonances with various molecular rotational and vibrational transitions.

Sensitized Fluorescence in Vapors of Alkali Atoms XIV. Temperature Dependence of Cross Sections for 72P1/2–72P3/2 Mixing in Cesium, Induced in Collisions with Noble Gas Atoms

1974 ◽  
Vol 52 (11) ◽  
pp. 945-949 ◽  
Author(s):  
I. N. Siara ◽  
H. S. Kwong ◽  
L. Krause
Keyword(s):  
Temperature Dependence ◽  
Cross Sections ◽  
Noble Gas ◽  
Excitation Transfer ◽  
Sensitized Fluorescence ◽  
Alkali Atoms ◽  
Resonance Doublet ◽  
The Cross ◽  
Adiabatic Case

The cross sections for 72P1/2–72P3/2 excitation transfer in cesium, induced in collisions with noble gas atoms, have been determined in a series of sensitized fluorescence experiments at temperatures ranging from 405 to 630 K. The cross sections which lie in the range 0.06–20 Å2, exhibit a temperature dependence which, however, is less pronounced than in the more adiabatic case of the cesium resonance doublet.

Polarization transfer and relaxation induced in collisions of excited alkali atoms

1976 ◽  
Vol 54 (6) ◽  
pp. 709-719 ◽  
Author(s):  
E. I. Dashevskaya ◽  
E. E. Nikitin
Keyword(s):  
Fine Structure ◽  
Polarization Transfer ◽  
Approximate Theory ◽  
Fine Structure Splitting ◽  
Alkali Atoms ◽  
Resonance Doublet ◽  
Structure Splitting

We present an approximate theory of intramultiplet mixing, relaxation, and polarization transfer in excited alkali atoms, valid for all magnitudes of the fine-structure splitting. The theory is developed as the generalization of the previously postulated theory of fine-structure mixing induced in adiabatic and quasiresonant collisions. In the adiabatic region, the theory predicts a change in the sign of the coefficient for polarization transfer between the components j = 1/2 and,j = 3/2 of the 2P resonance doublet, as the Massey parameter for this transition changes.

Inelastic collisions between excited alkali atoms and molecules. V. Sensitized fluorescence in mixtures of sodium with N2, H2, HD, and D2

1968 ◽  
Vol 46 (19) ◽  
pp. 2127-2131 ◽  
Author(s):  
M. Stupavsky ◽  
L. Krause
Keyword(s):  
Cross Sections ◽  
Ground State ◽  
Resonance Effect ◽  
Excitation Transfer ◽  
Inelastic Collisions ◽  
Sodium Vapor ◽  
Sensitized Fluorescence ◽  
Atoms And Molecules ◽  
Alkali Atoms ◽  
Exciting Beam

3 2P1/2 ↔ 3 2P3/2 excitation transfer in sodium, induced in inelastic collisions with ground-state N2, H2, HD, and D2 molecules, has been investigated in a series of sensitized fluorescence experiments. Mixtures of sodium vapor at a pressure of 5 × 10−7 Torr, and the gases, were irradiated with each NaD component in turn, and the fluorescence which contained both D components was monitored at right angles to the direction of the exciting beam. Measurements of the relative intensities of the NaD fluorescent components yielded the following collision cross sections for excitation transfer. For Na–N2 collisions: Q12(2P1/2 → P3/2) = 144 Å2, Q21(2P1,2 ← 2P3/2) = 76 Å2 for Na–H2 collisions: Q12 = 80 Å2, Q21 = 42 Å2. For Na–HD collisions: Q12 = 84 Å2, Q21 = 44 Å2. For Na–D2 collisions: Q12 = 98 Å2, Q21 = 52 Å2. The cross sections Q21 exhibit a slight resonance effect between the atomic and molecular rotational transitions.

Inelastic collisions between excited alkali atoms and molecules. VII. Sensitized fluorescence and quenching in mixtures of rubidium with H2, HD, D2, N2, CH4, CD4, C2H4, and C2.H6

1970 ◽  
Vol 48 (22) ◽  
pp. 2761-2768 ◽  
Author(s):  
E. S. Hrycyshyn ◽  
L. Krause
Keyword(s):  
Cross Sections ◽  
Photon Counting ◽  
Inelastic Collisions ◽  
Exciting Light ◽  
Rubidium Vapor ◽  
Sensitized Fluorescence ◽  
Alkali Atoms ◽  
Order Of Magnitude ◽  
Resonance Doublet ◽  
Intensity Ratios

52P1/2 ↔ 52P3/2 mixing and 52S1/2 ← 52P1/2, 2P3/2 quenching in rubidium, induced in collisions with ground state H2, HD, D2, N2, CH4, CD4, C2H4, and C2H6 molecules, have been investigated using methods of sensitized fluorescence. The rubidium vapor mixed with each of the gases was excited in turn by each component of the rubidium resonance doublet, and the resulting fluorescence, emitted at right angles to the direction of the exciting light, was resolved into the two fine-structure components whose intensity ratios were measured in relation to the gas pressure using photon counting techniques. The measurements yielded the following cross sections for the mixing and quenching collisions.For H2: Q12(2P1/2 → 2P3/2) = 11 Å2, Q21(2P1/2 ← 2P3/2) = 15 Å2, Q10(2S1/2 ← 2P1/2) = 6 Å2, Q20(2S1/2 ← 2P3/2) = 3 Å2.[Formula: see text]The mixing cross sections agree with theoretical values within an order of magnitude.

Transfer of Electronic Excitation between the 62P3/2 and 62P1/2 States of Rubidium Induced by Collisions with Rubidium Atoms

1974 ◽  
Vol 52 (17) ◽  
pp. 1635-1640 ◽  
Author(s):  
Paul W. Pace ◽  
J. B. Atkinson
Keyword(s):  
Fine Structure ◽  
Cross Sections ◽  
Electronic Excitation ◽  
Empirical Relationship ◽  
Optical Excitation ◽  
Nitrogen Laser ◽  
Rubidium Vapor ◽  
Rubidium Atoms ◽  
Structure Splitting ◽  
The Cross

The cross sections for excitation transfer between the 62P fine structure levels of rubidium, induced in collisions with ground state rubidium atoms, have been measured using a nitrogen laser pumped dye laser as the optical excitation source in a fluorescence experiment. Rubidium vapor was irradiated with each component of the 2P rubidium doublet in turn, and measurements of the relative intensities of fluorescence yielded the following cross sections: [Formula: see text] These results are consistent with the empirical relationship between the magnitude of the cross sections and the fine structure splitting that has previously been established for the alkalis.

Coherence Transfer Between the 32P1/2 and 32P3/2 States in Sodium, Induced in Collisions with Noble Gas Atoms

1973 ◽  
Vol 51 (9) ◽  
pp. 993-997 ◽  
Author(s):  
B. Niewitecka ◽  
L. Krause
Keyword(s):  
Cross Sections ◽  
Noble Gas ◽  
Excitation Transfer ◽  
Resonance Radiation ◽  
Buffer Gas ◽  
Resonance Fluorescence ◽  
Sodium Vapor ◽  
Coherence Transfer ◽  
Sensitized Fluorescence ◽  
Simultaneous Transfer

Coherence transfer accompanying 32P1/2 → 32P3/2 excitation transfer in sodium, induced in collisions with noble gas atoms, has been investigated using methods of sensitized fluorescence. Oriented 32P1/2 sodium atoms were produced by irradiating a mixture of sodium vapor and a noble gas with D1σ+ resonance radiation, and their subsequent collisions with the buffer gas atoms resulted in the simultaneous transfer of coherence and excitation from the 2P1/2 state to the 2P3/2 state. Measurements of the ratio of circular polarizations of the D2 sensitized fluorescence and D1 resonance fluorescence resulted in the following cross sections for coherence transfer. Na–He : 7.1 ± 0.7 Å2; Na–Ne : 6.2 ± 0.6 Å2; Na–Ar : 12.0 ± 1.2 Å2; Na–Kr : 6.8 ± 0.7 Å2; Na–Xe : 6.9 ± 0.7 Å2.

82D3/2 ↔ 82D5/2 excitation transfer in rubidium induced in collisions with ground-state Rb atoms

1981 ◽  
Vol 59 (4) ◽  
pp. 548-554 ◽  
Author(s):  
M. Głódz ◽  
J. B. Atkinson ◽  
L. Krause
Keyword(s):  
Fine Structure ◽  
Cross Sections ◽  
Ground State ◽  
Photon Counting ◽  
Excitation Transfer ◽  
Atomic Fluorescence ◽  
Rubidium Vapor ◽  
Two Photon ◽  
Photon Excitation ◽  
Structure State

Cross sections for inelastic transfer between the 82D3/2 and 82D5/2 fine-structure states in rubidium, induced in resonant collisions with ground-state Rb atoms, have been determined using an experimental method involving two-photon excitation of atomic fluorescence. Rubidium vapor in a fluorescence cell was irradiated with pulses of 641 nm radiation from a N2 laser-pumped dye-laser tuned to excite one of the 82D states. The resulting fluorescence included the direct component originating from the optically excited state and a sensitized component arising from the other fine-structure state populated by collisions. Relative intensities of the fluorescent components, determined by photon-counting techniques, yielded the cross sections for excitation transfer: Q(2D3/2 → 2D5/2) = 8.1 × 10−13 cm2; Q(2D3/2 ← 2D5/2) = 5.5 × 1013 cm2; as well as [Formula: see text], the effective quenching cross section. The excitation transfer cross sections which are considered accurate to within ±20% are in the ratio predicted by the principle of detailed balancing.

52P1/2 ↔ 52P3/2 excitation transfer in rubidium induced in collisions with CH4, CH2D2, and CD4 molecules

1980 ◽  
Vol 58 (7) ◽  
pp. 1047-1048 ◽  
Author(s):  
R. A. Phaneuf ◽  
L. Krause
Keyword(s):  
Energy Transfer ◽  
Temperature Dependence ◽  
Isotope Effect ◽  
Cross Sections ◽  
Noble Gas ◽  
Rotational Energy ◽  
Excitation Transfer ◽  
Sensitized Fluorescence ◽  
Temperature Range ◽  
Rotational Energy Transfer

The temperature dependence of cross sections for 52P1/2 ↔ 52P3/2 excitation transfer in rubidium, induced in collisions with CH4, CH2D2, and CD4 molecules, has been investigated using methods of sensitized fluorescence over a temperature range 300–650 K. The cross sections, which are of the order of 30 Å2 and which exceed similar cross sections for collisions with noble gas atoms by at least two orders of magnitude, exhibit an isotope effect which is ascribed to the phenomenon of electronic-to-rotational energy transfer.

Exciton fine structure splitting of single InGaAs self-assembled quantum dots

2004 ◽  
Vol 21 (2-4) ◽  
pp. 175-179 ◽  
Author(s):  
A Högele ◽  
B Alèn ◽  
F Bickel ◽  
R.J Warburton ◽  
P.M Petroff ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Fine Structure ◽  
Fine Structure Splitting ◽  
Structure Splitting ◽  
Self Assembled
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