An apparatus comprising an optical multiplexer/demultiplexer having a set of input ports and a set of output ports, the optical multiplexer/demultiplexer configured to demultiplex a wavelength division multiplexed optical signal to one port of the set of input ports, and to output a plurality of demultiplexed wavelength channels to one of a plurality of subsets of output ports within the set of output ports. The apparatus comprises an optical switch configured to route the wavelength division multiplexed signal to a selected one of the input ports, thereby causing the plurality of demultiplexed wavelength channels to be output by the optical multiplexer/demultiplexer to selected ones of the plurality of subsets of output ports.