A micro-photonics device is described that includes a substrate and a plurality of optical and electrical components mounted on the substrate. The optical and electrical components form a transmitter and a receiver. A wall is mounted on the substrate to physically separate some of the components from other components to prevent electrical and optical interference between the transmitter and receiver. The wall mounted on the substrate may also be mounted with electrical and optical components of the micro-photonics device. In this case, the wall physically separates the components mounted on the substrate from the components mounted on the wall to prevent electrical and optical interference. Moreover, the wall with the mounted components may simply be attached to a side surface of the substrate.