Abstract: An optical multi-port element with an acousto-optical modulator (AOM) has at least two monomode optical waveguide connections, at one side thereof. The end surfaces of the waveguides disposed in the focal plane of a lens situated between the optical waveguides and the acousto-optical modulator. In order to obtain a construction which can be adjusted in a simple manner and which has low attenuation, with a small overall length, it is provided that at least one side of the AOM (1) a single lens (2,3,31) is disposed with its optical axis aligned to the transmission axis of the AOM (1), and that the optical wave-guides (4 to 6, 18 to 20 or 27,28) are disposed with their axes parallel to one another and spaced from the optical axis of the lens (2,3,31) in such a manner that parallel beams (14 to 17), leading from the lens (2,3,31) to the AOM (1), are directed to the active region of the AOM (1) at the Bragg angle to the optical axis.