Switching optical signals containing a plurality of spectral channels characterized by a predetermined channel spacing is described. A selected beam deflector array may be selected from among a plurality of available beam deflector arrays configured to accommodate spectral channels of different channel spacings. The selected beam deflector array is configured to accommodate spectral channels of the predetermined channel spacing. The spectral channels are selectively optically coupled to the selected beam deflector array, which selectively optically couples the spectral channels between one or more input ports and one or more output ports.