Two-photon mapping of local molecular orientations in hexaphenyl nanofibers

2004 ◽  
Vol 237 (4-6) ◽  
pp. 423-429 ◽  
Author(s):  
Jonas Beermann ◽  
Sergey I Bozhevolnyi ◽  
Vladimir G Bordo ◽  
Horst-Guenter Rubahn
Keyword(s):  
2011 ◽  
Vol 2011 (5) ◽  
pp. pdb.top111-pdb.top111 ◽  
Author(s):  
V. Nikolenko ◽  
E. Fino ◽  
R. Yuste

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Francesco Pastorelli ◽  
Nicolò Accanto ◽  
Mikkel Jørgensen ◽  
Niek F. van Hulst ◽  
Frederik C. Krebs

2004 ◽  
Vol 1 (5) ◽  
pp. 264-268 ◽  
Author(s):  
J Beermann ◽  
C Marquart ◽  
S I Bozhevolnyi
Keyword(s):  

2008 ◽  
Vol 16 (22) ◽  
pp. 17302 ◽  
Author(s):  
Jonas Beermann ◽  
Sergey M. Novikov ◽  
Thomas Søndergaard ◽  
Alexandra Boltasseva ◽  
Sergey I. Bozhevolnyi

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.


Author(s):  
David W. Piston

Two-photon excitation fluorescence microscopy provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging. 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 our fluorescence experiments, the final excited state is the same singlet state that is populated during a conventional fluorescence experiment. Thus, the fluorophore exhibits the same emission properties (e.g. wavelength shifts, environmental sensitivity) used in typical biological microscopy studies. 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.


1996 ◽  
Vol 43 (9) ◽  
pp. 1765-1771 ◽  
Author(s):  
M. W. HAMILTON and D. S. ELLIOTT

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