A system includes an optical transmitter package comprising an optical transmitter to generate optical transmission signals based on electrical transmission signals. The system also includes an optical receiver package comprising an optical receiver to generate electrical reception signals based on optical reception signals. The system further includes a printed circuit board (PCB) on which the optical transmitter package and the optical receiver package are mounted. The PCB includes a heat generating circuit component. The optical transmitter package can be mounted to the PCB to subjected to less heat from the heat generating circuit component than the optical receiver package.