An electro‐optical pulse selection system for mode‐locked cw lasers is described. The repetition rate of the exciting pulses can be chosen by electronically dividing the mode locker drive frequency. The shortest repetition time for pulse picking is 3 μs. The optics, electronics, alignment procedure, and adaptation to the detection system are outlined. We use this equipment for measuring the decay of fluorescence and of emission anisotropy of biological molecules.