Patent ID: 8913899

Claim:
A system, comprising: a plurality of optical line cards; a plurality of lasers that are external to the optical line cards; and an optical-power-distribution (OPD) subsystem disposed between the plurality of lasers and the plurality of line cards to route optical signals generated by the lasers to the line cards, wherein each of the optical line cards is configured to use a respective optical signal received from the OPD subsystem to provide an optical-reference signal for coherent detection of a modulated optical signal received by the optical line card; and wherein the OPD subsystem comprises: an optical-power combiner having a plurality of input ports and an output port; and a first optical-power router having an input port and a plurality of output ports, wherein: the plurality of input ports of the optical-power combiner are coupled to the plurality of lasers so that each input port is either idle or configured to receive an optical signal generated by one of the lasers; the optical-power combiner is configured to combine the optical signals applied to the input ports thereof to produce a combined optical signal at the output port thereof; the input port of the first optical-power router is coupled to the output port of the optical-power combiner to receive an optical signal corresponding to the combined optical signal; and the first optical-power router is configured to split the received optical signal to produce a plurality of optical output signals at the output ports thereof and apply said optical output signals to a corresponding subset of the optical line cards.