Picosecond laser-fluorometer with simultaneous time and wavelength resolution for monitoring decay spectra of photoinhibited Photosystem II particlesat 277 K and 10 K

The present study describes a novel fluorometer system which permits the si multaneous monitoring of the time and wavelength dependence of chlorophyll fluorescence in the picosecond time domain. The key element of this equipme nt is a microchannel-plate photomultiplier with delay-line anode. The compa ratively short acquisition times in combination with full spectral and temp oral resolution of this device are of high advantage, especially for measur ements on photosynthetic samples at cryogenic temperatures. For a convenien t numerical data evaluation of complex overlapping spectra a decay-associat ed gaussian deconvolution technique was installed by developing a fitting p rogram with graphical user-interface. In order to illustrate the potential of the new set-up, surface plots and decay spectra gathered from measuremen ts with anaerobically photoinhibited Photosystem II particles at 277 K and 10 K are presented.