A device for the optical splitting and modulation of monochromatic coherent electromagnetic radiation, in particular light beams and/or laser beams, contains a beam source, an acousto-optical element disposed downstream of the latter and serving for splitting the beam generated by means of the beam source into a number of partial beams, a modulator and also a signal generator for applying to the acousto-optical element an electrical signal for splitting the beam. The device is intended to be developed to the effect that in conjunction with a simple and functionally reliable construction and independently of the number of beams emitted by the beam source, the intensity of the individual split partial beams can be kept constant. For this purpose, it is proposed that the modulator is embodied as an acousto-optical modulator disposed downstream of the acousto-optical element, and that the acousto-optical modulator is fed the split partial beams for modulation, and the acousto-optical modulator can be driven with additional high-frequency electrical signals.