Selection of pulse groups or single pulses out of a train of ultrashort light pulses by absorption from excited levels

Abstract Selection of pulse groups or single pulses is achieved by absorption from higher electronic levels of organic molecules excited by two-photon absorption. The energy of selected pulses is only reduced to half the initial value. This two-step absorber can be used in combination with a saturable single-photon absorber to increase selectivity. Pulses are selected from the former part of the train.