Two years ago Seth Olsen and I published a paper, pointing out that in the Green Fluorescent Protein there should be a dark excited state [i.e. a state which does not contribute significantly to the one-photon absorption cross section] which should have a large two photon absorption (TPA) cross section. This has a natural explanation in terms of a valence bond description of the three lowest lying singlet states of the chromophore.
We were very pleased that last year there was a long article in Nature methods, Two-photon absorption properties of fluorescent proteins, by Drobizhev et al.. It contains the data below. The peak on the left (around 650 nm) is due to TPA from the dark excited state.
The authors were unaware of our work, but cite it in their latest paper on vibronic effects in two-photon absorption.
Subscribe to:
Post Comments (Atom)
A very effective Hamiltonian in nuclear physics
Atomic nuclei are complex quantum many-body systems. Effective theories have helped provide a better understanding of them. The best-known a...
-
Is it something to do with breakdown of the Born-Oppenheimer approximation? In molecular spectroscopy you occasionally hear this term thro...
-
If you look on the arXiv and in Nature journals there is a continuing stream of people claiming to observe superconductivity in some new mat...
-
I welcome discussion on this point. I don't think it is as sensitive or as important a topic as the author order on papers. With rega...
No comments:
Post a Comment