An optical switch, in which optical input signals are fed together with pumping light to input waveguides. Output waveguides and/or conducting waveguides connected downstream thereof are doped with a dopant which effects amplification of the signal light. A wavelength-selective coupling element is arranged on the output side for the purpose of coupling out the pumping light. This improves signal quality, since the interfering pumping light is virtually no longer present downstream of the wavelength-selective coupling element.