Resonance energy transfer accuracy

Pelet, S., Previte, M. J. and So, P. T. (2006). Comparing the quantification of Forster resonance energy transfer measurement accuracies based on intensity, spectral, and lifetime imaging. J. Biomed. Opt. 11, 34017. 

Fluorescence resonance energy transfer (FRET) is another powerful technique for the determination of structural and functional information using fluorescent proteins. FRET is a physical phenomenon in which the distance between donor and acceptor fluorophores can be determined with reasonable accuracy [67]. This phenomenon was harnessed to study the c-Crk-II signaling protein, which is a substrate of the c-Abl protein kinase [68]. Using... 

The ability to measure intensities and lifetimes of both donor and acceptor emission with high accuracy and excellent signal-to-background, coupled with the unusually large R s, makes luminescence resonance energy transfer a potentially powerful technique for measuring distances in biological systems. 

In the first part of this article we have briefly summarized the study of resonant dipole-dipole energy transfer collisions between Rydberg atoms. Due to the long range of the dipole-dipole interaction the collision process can be understood with nearly spectroscopic accuracy, and this understanding forms the basis for understanding dipole-dipole interactions in a frozen Rydberg gas. 

As shown by Fig. 14.15, the resonances occur near zero field, and it is easy to calculate the small Stark shifts with an accuracy greater than the linewidths of the collisional resonances. As a result it is straightforward to use the locations of the collisional resonances to determine the zero field energies of the p states relative to the energies of the s and d states. Since the energies of the ns and nd states have been measured by Doppler free, two photon spectroscopy,22 these resonant collision measurements for n = 27, 28, and 29 allow the same precision to be transferred to the np states. If we write the quantum defect dp of the K np states as... 

Metastable muonium atoms in the 2s state have been produced with a beam foil technique at LAMPF and at the Tri University Meson Physics Facility (TRI-UMF) at Vancouver, Canada. Only moderate numbers of atoms could be obtained. The velocity resonance nature of the electron transfer reaction results in a muonium beam at keV energies. Very difficult and challenging experiments using electromagnetic transitions in excited states, particularly the 2 Si/2 2 Pi/2 classical Lamb shift and 2 Si/2-2 P3/2 splitting could be induced with microwaves. However, the achieved experimental accuracy at the 1.5 % level [18,19,20], does not represent a severe test of theory yet. 

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