Absorption of picosecond light pulses by selectively excited electronic molecular states

An investigation is made of the formation of single pulses and of pulse trains, and of selection of one or several pulses from a train by two-photon absorption of light in an excited system. Estimates and measurements are reported of the efficiency of a two-photon absorber used in combination with a onephoton saturable absorber. The results are also given of a probe-beam study of the kinetic processes in molecules.