Excitation, three-photon

Schrader M, Bahimann K and Hell S W 1997 Three-photon-excitation microscopy Theory, experiment, and applications Optik 104 116-24... 

In order to relate the formal expression (41) to the experiment of Section III, we now specialize the discussion to the case of one- versus three-photon excitation, limiting attention for simplicity to fragmentation of diatomic systems, relevant to the experiments of Refs. 30, 32, 33, 35, and 39. We note later, however, that our conclusions are general and equally applicable to other excitation schemes and to ionization processes. 

We follow the convention adopted by the literature on coherent control via the one- versus three-photon excitation method, where the frequency of the three-photon field is denoted coi and that of the one-photon field is denoted C03. 

Dipole matrix elements, one- vs. three-photon excitation, coherence spectroscopy, 163—166... 

In a first example, Brumer and Shapiro proposed to simultaneously excite an exit channel via two different excitation pathways. The wave functions corresponding to the two pathways (usually one- and three-photon excitation, y i = 3 y2) may then interfere constructively or destructively depending on the phase relation between the two lasers used [1,2]. 

Maiti, S., J.B. Shear, R.M. Williams, W.R. Zipfel, and W.W. Webb. 1997. Measuring serotonin distribution in live cells with three-photon excitation. Science 275 530-532. 

Figure 7.4 Linear UV-absorption and three-photon excitation spectra of complexes 1 and 2.

FIGURE 3 Illustration of coherent phase control by one- and three-photon excitation in the cases of (a) no intermediate resonances and (b) a quasi-bound state at the two-photon level that introduces a channel phase shift of 13- [Reproduced with permission from Fiss, J. A., Khachatrian, A., Truhins, K., Zhu, L., Gordon, R. J., and Seideman, T. (2000). Phys. Rev. Lett. 85, 2096.]... 

FIGURE 4 Theoretical calculation of the coherent phase control of the photodissociation of IBr by one- and three-photon excitation. [Reproduced with permission from Chan, C. K., Brumer, R, and Shapiro, M. (1991). J. Chem. Phys. 94,2688. Copyright American Institute of Physics.]... 

The probability P (E) of observing the final state n at energy E is given as " P (E) = An(E) 2. In accord with Eq. (3.48) we identify the components associated with one-photon excitation P (E), three-photon excitation p2 E), and one- photon/three-photon interference Pj,I3 (E) so that... 

Several articles and reviews on different aspects of multi-photon excitation of biomolecule system are available. For example, Birch [11] consideraticms concentrate mainly on the impact of multi-photon techniques to the time-resolved fluorescence spectroscopy. Lakowicz and Gryczynski [12] have discussed examples of three-photon excited fluorescence. Rehms and Callis studied the two-photon excited fluorescence emission of aromatic amino acids [13]. Kierdasz et al analyzed emission spectra of Tyrosine- and Tryptophan-containing proteins using one-photon (270-3 10 nm) and two-photon (565-6 10 nm) excitation [14]. 

Lakowicz, J. R., and Gryczynski, I. (1999). Three-photon excitation of fluorescence. In Applied Fluorescence in Chemistry, Biology and Medicine, Rettig, W., Strehmel, B., Schrader, S., and Seifert, H. (Eds), Springer-Verlag, Berlin Heidelberg, pp. 137. 

Maiti, S., Shear, J. B., Williams, R. M., Zipfel, W. R., and Webb, W. W. (1997) Measuring Serotwiin Distribution in Live Ceils with Three-Photon Excitation. Science 275 530 - 532. 

Our conclusions based on estimation (51) need support from strict simulations, which, however, are not easily obtained because we cannot select one-photon or three-photon pumping using strict equations. This means that we can use only some fingerprints of one- or three-photon excitations. One of these fingerprints is tire transmission of the pump field... 

Benzene still provides fruitful labour for the dedicated photochemist. A three photon excitation study of the So(A, ) - SjfBju) transition in the neat liquid shows that under this condition internal states exist which make the experimentally observed 3 photon allowed pathway. A photochemical study of both benzene and pyridine shows that Dewar benzene structure formation involves S1-S2 state mixing by irradiation at 253.7 nm. For pyridine in a xenon matrix all photochemical reactions are quenched and evidence for the formation triplet state of this molecule is produced for the first time. The photophysical significance of PE surface geometries of the low... 

Since the electronic selection rule is AA = 0, 1, 2, 3, three-photon excitations from, for example, a + state, can terminate in 1 An and 1 u states as well as the + and 1n,1 states accessible via one-photon transitions. 

Earlier absorption studies had identified a progression of parallel bands (traditionally labeled the C—X system) [181] in much the same energy region as the B—transition. These were long presumed to be associated with the 3pj(a 2) - 3aj promotion, but this presumption was shown to be invalid in 1978 following the discovery and characterization of the C—X system by Nieman and Colson [220]. The one-photon absorption spectrum shows no evidence of the C —X transition, but the spectroscopy of the first few i 2 levels of the C state of both NHj and ND3 is now well established from analysis of one-color two- and/or three-photon excitation spectra [227,228]. 

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