scholarly journals Optically driving the radiative Auger transition

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Clemens Spinnler ◽  
Liang Zhai ◽  
Giang N. Nguyen ◽  
Julian Ritzmann ◽  
Andreas D. Wieck ◽  
...  
Keyword(s):  
Excited States ◽  
Photon Absorption ◽  
Thz Spectroscopy ◽  
Fluorescence Signal ◽  
Resonance Fluorescence ◽  
Transition Form ◽  
Coulomb Interactions ◽  
Auger Process ◽  
Auger Transition ◽  
Semiconductor Quantum Dot

AbstractIn a radiative Auger process, optical decay leaves other carriers in excited states, resulting in weak red-shifted satellite peaks in the emission spectrum. The appearance of radiative Auger in the emission directly leads to the question if the process can be inverted: simultaneous photon absorption and electronic demotion. However, excitation of the radiative Auger transition has not been shown, neither on atoms nor on solid-state quantum emitters. Here, we demonstrate the optical driving of the radiative Auger transition, linking few-body Coulomb interactions and quantum optics. We perform our experiments on a trion in a semiconductor quantum dot, where the radiative Auger and the fundamental transition form a Λ-system. On driving both transitions simultaneously, we observe a reduction of the fluorescence signal by up to 70%. Our results suggest the possibility of turning resonance fluorescence on and off using radiative Auger as well as THz spectroscopy with optics close to the visible regime.

Fluorescence anisotropy in indole under two-photon excitation in the spectral range 385–510 nm

2018 ◽  
Vol 20 (30) ◽  
pp. 19922-19931 ◽  
Author(s):  
M. E. Sasin ◽  
A. G. Smolin ◽  
K.-H. Gericke ◽  
E. Tokunaga ◽  
O. S. Vasyutinskii
Keyword(s):  
Propylene Glycol ◽  
Excited States ◽  
Spectral Range ◽  
Ground State ◽  
Fluorescence Anisotropy ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Photon Excitation ◽  
Molecular Ground State

This paper presents the detailed study of two-photon excited fluorescence in indole dissolved in propylene glycol produced by two-photon absorption from the molecular ground state to several high lying excited states.

scholarly journals Astrophysical relevance of the low-energy dipole strength of 206Pb

2018 ◽  
Vol 178 ◽  
pp. 04003
Author(s):  
A.P. Tonchev ◽  
N. Tsoneva ◽  
S. Goriely ◽  
C. Bhatia ◽  
C.W. Arnold ◽  
...  
Keyword(s):  
Excited States ◽  
Experimental Information ◽  
Neutron Separation Energy ◽  
Resonance Fluorescence ◽  
Photon Beams ◽  
Dipole Strength ◽  
Nuclear Resonance Fluorescence ◽  
Decay Widths ◽  
Linearly Polarized ◽  
Important Branch

The dipole strength of 206Pb was studied below the neutron separation energy using photon scattering experiments at the HIGS facility. Utilizing the technique of nuclear resonance fluorescence with 100% linearly-polarized photon beams, the spins, parities, branching ratios and decay widths of excited states in 206Pb from 4.9 - 8.1 MeV have been measured. The new experimental information is used to reliably predict the neutron capture cross section of 205Pb, an important branch point nucleus along the s-process path of nucleosynthesis.

Interaction of UV radiation with DNA helices

2009 ◽  
Vol 81 (9) ◽  
pp. 1635-1644 ◽  
Author(s):  
Dimitra Markovitsi
Keyword(s):  
Energy Transfer ◽  
Excited States ◽  
Flash Photolysis ◽  
Photon Absorption ◽  
Base Pairs ◽  
Relaxation Energy ◽  
Double Helices ◽  
Fluorescence Upconversion ◽  
Theoretical Investigations ◽  
Franck Condon

Recent experimental and theoretical investigations dealing with model DNA double helices, composed of either adenine–thymine (A–T) or guanine–cytosine (G–C) base pairs, and G quadruplexes shed some light on the excited states populated by photon absorption and their relaxation, energy transfer among bases, and one-photon ionization. These studies revealed that the Franck–Condon excited states of DNA helices cannot be considered as the sum of their monomeric constituents because electronic coupling induces delocalization of the excitation over a few bases. Energy transfer takes place via intraband scattering in less than 100 fs. The fluorescence lifetimes of DNA helices detected by fluorescence upconversion and corresponding mainly to ππ* transitions are longer than that of an equimolar mixture of nucleotides; the only exception was observed for alternating G–C polymers. Moreover, nanosecond flash photolysis experiments showed that organization of bases within single and double helices may lead to a lowering of their ionization potential. Finally, the first determination regarding the time-scale needed for the formation of T dimers, the (6–4) adducts, was determined for the single strand (dT)20.

Excited States and Two-Photon Absorption of Some Novel Thiophenyl Pt(II)−Ethynyl Derivatives

2007 ◽  
Vol 111 (2) ◽  
pp. 244-250 ◽  
Author(s):  
Eirik Glimsdal ◽  
Marcus Carlsson ◽  
Bertil Eliasson ◽  
Boris Minaev ◽  
Mikael Lindgren
Keyword(s):  
Excited States ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon

scholarly journals Trans-cis Photoisomerization of a Biomimetic Cyclocurcumin Analogue Rationalized by Molecular Modelling

2021 ◽  
Author(s):  
Raúl Losantos ◽  
Jeremy Pecourneau ◽  
Maxime Mourer ◽  
Stephane Parant ◽  
Andreea Pasc ◽  
...  
Keyword(s):  
Excited States ◽  
Density Functional ◽  
Parent Compound ◽  
Photon Absorption ◽  
Present Contribution ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Photochemical Properties ◽  
A Minor ◽  
Π State

<div> <p>Cyclocurcumin is a natural compound extracted from turmeric and showing, in addition to antiinfective, antibacterial, and intinflammatory capabilities, solvent-dependent phtoswitching ability. The solvent-dependent photochemistry of cyclocurcumin has been rationalized on the basis of a competition between π-π* and n-π* states. Recently we have reported the synthesis of a biomimetic analogue showing enhanced photochemical properties and in particular presenting photoswitching capacity in various media. In the present contribution we rely on the use of molecular modeling and simulation, incuding density functional and wavefunction based methods to explore the excited states potential energy surface landscape. We see that the addition of a carbon-carbon double bond to the core of the natural compounds favors the population of the π-π* state, whatever the choice of the solvent, and hence leads to photoisomerisation, with fluorescence reduced to only a minor channel, rationalizing the experimental observations. In addition, the two photon absorption cross section is also strongly increased compared to the parent compound, paving the way to the use in biologically oriented applications.</p></div>

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