Wavelength-unresolved fluorescence

The mby fluorescence emission is induced by laser excitation and can be revealed through a monochromator and a CCD detector. The wavelength and the power of the laser excitation are not restrictive at low pressure, and even few milliwatts of the 647.1-nm excitation line of a Kr ion laser can induce an easily detectable fluorescence emission. Any lower wavelength can be used as well. Typical exciting laser fines used are the 488- and 514.5-nm emissions of an Ar ion laser. Things are more complicated at pressures of 100 GPa, where the mby signal decreases in intensity and the two components are unresolved [235, 248-251]. Recently, it has been demonstrated by means of x-ray diffraction that... 

At this point a comparison with other measurements on cyanobacterial PS I particles is of interest. (5) reported also a very fast decay component of - 14 ps in a PS I particle from Phormidium which was of simUar size as ours. They analyzed their decays in terms of a biexponential model with the second lifetime being as low as 84 ps. Thus, assuming a small amount of unresolved longer-lived components, their kinetics may be very similar to ours. However, since they did not wavelength-resolve the fluorescence but observed mostly the... 

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