Three-parametric model of formation of photosynthesizing organisms fluorescence response under laser pulse excitation

A three-parametric model has been suggested for fluorescence-accompanied photophysical processes in photosynthesizing organisms under laser pulse excitation. The model parameters include the excitation cross section of chlorophyll-$a$ molecules determined both by direct absorption of exciting radiation and by energy transfer from auxiliary pigments, the lifetime of the excited state in these molecules defined by their linear deactivation rate, and the singlet-singlet annihilation constant.