An optical backplane is provided that has at least first and second side walls that are generally parallel to one another and at least one optical relay element disposed on at least one of the parallel side walls. An optical signal is coupled into the optical backplane through an entrance facet of the backplane. The optical signal is maintained within the optical backplane by internal reflection at the parallel side walls of the backplane. The optical relay element receives the optical signal reflected off of one of the side walls and reflects and refocuses the optical signal to guide the optical signal and prevent it from diverging as it propagates through the backplane from the entrance facet to the exit facet.