Cross excitation

Ramakrishna G, Goodson T III, Rogers-Haley JE, Cooper TM, McLean DG, Urbas A (2009) Ultrafast intersystem crossing excited state dynamics of platinum acetylide complexes. J Phys Chem C 113 1060-1066... 

D is the sum of the remaining donor fluorescence in the donor channel (/p s) > and of leak-through components of sensitized emission back into the donor channel (/ ) and of cross-excited acceptors back into the donor channel (/ J). 

S contains energy transfer (/ ), leak-through from the donor minus FRET population (Ijj-s) anemission from cross-excited acceptors (T)). 

Ta 1D Acc Acc Don cross-excited (at l x) signal of unquenched donors leaking through in the acceptor channel... 

Ta 2S Acc Acc s.e. (acceptor) s.e. in acceptor channel at l x this signal derives from the small population of cross-excited donors that leads to FRET... 

Ja lD-S Acc Acc Don3 leak-through of the cross-excited, (partly) quenched donor signal in the s.e. channel... 

Finally, A is the output gray value after the acceptor channel9 scaling (g3) of the fraction of acceptor fluorescence in the acceptor channel (FJ), which depends on the acceptor quantum yield (Qa) and on the amount of acceptors NA excited at a x (t il A ), of (usually very minor) contributions of donor fluorescence cross-excited at and leaking into the acceptor channel ((No — ENs)fa< -DQdF d F) and of sensitized emission resulting from cross-excitation at 2 x (ENs dQaF 3) However, as... 

Relates signal from cross-excited donors in S to that in A (provided that emission filters are identical)... 

B) FRET efficiency as a function of Mg2+ ion concentration for the SB and BC vectors. The data have been fitted to a two-state ion binding model. Fluorescence emission spectra were recorded at 4 °C using an SLM-Aminco 8100 fluorimeter with modernized Phoenix electronics (ISS Inc., Champaign, IL, USA). Spectra were corrected for xenon lamp fluctuations and instrumental variations, and polarization artifacts were avoided by crossing excitation and emission polarizers at 54.7°. 

The dielectric is often assumed to be isotropic in order to simplify Eq. (8) by assuming transverse phonon-polaritons the extension to anisotropic media is straightforward (31). In the limit of very short pulse duration compared to the phonon-polariton oscillation period, the time-dependence of the excitation field can be treated as a delta function, and the phonon-polariton response is given by the impulse response function for the spatial excitation pattern used. If crossed excitation pulses are used, then it is simplest to describe the excitation and response in terms of the excitation wavevector or wavevector range. 

Excited configurations may be constructed by replacing one or more occupied SC orbitals with a virtual orbital, frequently taken from the same stack as the occupied orbital, in which case it is referred to as a vertical excitation. If the occupied orbital is replaced with a virtual from a different stack, then this is referred to as a cross excitation. A linear combination of the reference SC configuration and the excited configurations described above constitutes a so-called spin-coupled valence bond (SCVB) wavefunction. We use the term configuration to denote a particular orbital product, with all possible modes of coupling... 

P. Franken, Interference effects in the resonance fluorescence of crossed excited states. Phys. Rev. 121, 508 (1961)... 

Since it was found that a great part of the analyte released by sputtering consists of ground-state atoms, cross-excitation by d.c. [292],... 

Due to problems of significant crosstalk and cross-excitation between flu-orophores (see review by Zimmermann in this issue), multichannel imaging is very often performed sequentially even on potentially parallel acquisition systems like SBCMs. By switching excitations line by line, SBCMs possess a sequential acquisition mode that avoids mismatches between channels, which is not available for MBCMs. For most applications, however, the subsecond... 

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