A multi-chassis network device includes a plurality of nodes that operate as a single device within the network and a switch fabric that forwards data plane packets between the plurality of nodes. The switch fabric includes a set of multiplexed optical interconnects coupling the nodes. For example, a multi-chassis router includes a plurality of routing nodes that operate as a single router within a network and a switch fabric that forwards packets between the plurality of routing nodes. The switch fabric includes at least one multiplexed optical interconnect coupling the routing nodes. The nodes of the multi-chassis router may direct portions of the optical signal over the multiplexed optical interconnect to different each other using wave-division multiplexing.