An optoelectronic switch comprising: a first plurality of detector remodulators (DRMs) (C3, D1), each DRM having an integer number M of optical inputs and an integer number N of optical outputs; a second plurality of DRMs (C7, D5), each DRM having N optical inputs and M optical outputs; a passive optical switch fabric (C4+C5+C6, D2+D3+D4) connecting the N optical outputs of each of the first plurality of DRMs with the N optical inputs of each of the second plurality of DRMs, the path of an optical signal through the optical switch fabric depending upon its wavelength; wherein each DRM (C3, D1) of the first plurality of DRMs is configured to act as a tunable wavelength converter to select the desired path of an optical signal through the optical switch fabric (C4+C5+C6, D2+D3+D4); and wherein each of the first plurality of DRMs (C3, D1) includes a concentrator, the concentrator configured to aggregate optical signals received from any of the M inputs of that DRM and to buffer them according to the one of the plurality of second DRMs (C7, D5) that includes their destination port.