Systems and methods for optical communication are disclosed that include communicating data using one or more transceiver pairs coupled to a spatial-multiplexer (S-MUX); performing bi-directional transmissions over an elliptical core optical fiber to a spatial-demultiplexer (S-DEMUX) using spatial modes to communicate data in either direction between two transceiver pairs with low crosstalk and without optical circulators or wavelength-division multiplexing (WDM); and communicating data from the S-DEMUX with g one or more transceiver pairs.