Optically-coupled memory systems are disclosed. In one embodiment, a system memory includes a carrier substrate, and a controller attached to the carrier substrate and operable to transmit and receive optical signals, and first and second memory modules. The module substrate of the first memory module has an aperture formed therein, the aperture being operable to provide an optical path for optical signals between the controller and an optical transmitter/receiver unit of the second memory module. Thus, the system memory provides the advantages of “free space” optical connection in a compact arrangement of memory modules. In an alternate embodiment, the first memory module includes a beam splitter attached to the module substrate proximate the aperture. In another embodiment, the first and second memory modules are staged on the carrier substrate to provide an unobstructed path for optical signals. In another embodiment, the optical transmitter/receiver unit projects outwardly from the module substrate to provide an unobstructed path for optical signals.