Fs-transient Absorption and Fluorescence Upconversion after Two-Photon Excitation of Carotenoids in Solution and in LHC II

Author(s):  
P. J. Walla ◽  
P. A. Linden ◽  
G. R. Fleming
2004 ◽  
Vol 108 (29) ◽  
pp. 10340-10345 ◽  
Author(s):  
Patricia A. Linden ◽  
Jörg Zimmermann ◽  
Tobias Brixner ◽  
Nancy E. Holt ◽  
Harsha M. Vaswani ◽  
...  

2012 ◽  
Vol 116 (9) ◽  
pp. 2886-2890 ◽  
Author(s):  
Ilya Stepanenko ◽  
Viktor Kompanetz ◽  
Zoya Makhneva ◽  
Sergey Chekalin ◽  
Andrei Moskalenko ◽  
...  

Author(s):  
Václav Šebelík ◽  
Valentyna Kuznetsova ◽  
Heiko Lokstein ◽  
Tomáš Polívka

1993 ◽  
Vol 97 (32) ◽  
pp. 8378-8383 ◽  
Author(s):  
Martin U. Sander ◽  
Uwe Brummund ◽  
Klaus Luther ◽  
Juergen Troe

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3569-3573 ◽  
Author(s):  
T. ITOH ◽  
K. YAMANAKA ◽  
K. EDAMATSU ◽  
T. UOZUMI ◽  
Y. KAYANUMA

Exciton excited states of CuCl nanoparticles dispersed in NaCl matrix have been investigated by means of two-photon excitation and two-step IR transient absorption. In the two-photon excitation spectra, there appears a distinct absorption edge. As the particle radius decreases from 6.3nm to 1.6nm, the edge energy increases by about 0.15eV, more than twice as large as that of the lowest 1S state. The fast decay component of the IR transient absorption under pulsed excitation of the lowest 1S exciton shows a broad band which shifts from 0.2 to 0.4eV as the radius decreases from >10nm to 1.4nm. These absorption edge and band are ascribed to the nP-like Rydberg excited states of the confined excitons. The large energy shift indicates that the weak confinement which is typically valid for the lowest 1S exciton state in CuCl nanoparticles is no more applicable to these excited states. Their spectra and confinement effect are discussed in comparison with theoretical prediction.


Author(s):  
David W. Piston ◽  
Brian D. Bennett ◽  
Robert G. Summers

Two-photon excitation microscopy (TPEM) provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging and photochemistry. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10-5 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.


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