Fluid-cooling technology developed for printed circuit boards (PCBs) and electronics assemblies is combined with optical-based interconnect technology, thereby enabling efficient fabrication of PCBs with free-space optical bearers. Since cooling components such as fans and heat sinks are no longer required on the PCB, the PCB is thinner and makes better use of a cooling substrate by also using it to carry optical signals. A card or a backplane supporting a plurality of active components can combine optical signals and cooling aspects in support of those components.